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Glossary

| A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |

A

Acquisition Services

Provides technical support for obtaining hardware and software required to implement EPA's information technology requirements.

ASP (Active Server Page)

An ASP (Active Server Page) is an HTML page that includes one or more scripts (small embedded programs) that are processed on a Microsoft Web server before the page is sent to the user. An ASP is somewhat similar to a server-side include or a Common Gateway Interface (CGI) application in that all involve programs that run on the server, usually tailoring a page for the user. Typically, the script in the Web page at the server uses input received as the result of the user's request for the page to access data from a database and then build or customize the page "on the fly" before sending it to the requester.

Agency Desktop Connectivity Services

Provide a wide range of services designed to ensure reliable, and efficient operation and maintenance of the network infrastructure.

Aliases

An alias is a symbolic link which points to a specified directory. NCC recommends that aliases be created at the TSSMS level only (i.e http://www.epa.gov/water/for /public/data/watrhome/web). Aliases beneath the TSSMS Level can complicate site management. For more information, refer to the Web Guide's Alias

page.

Approval Memo

The approval memo is used to help ensure that someone is taking responsibility for information published on an EPA Web site, located on an EPA server. The letter addresses issues related to using an EPA server, complying with EPA Web site guidelines, and ensuring information is appropriate for public access.

Archiving

An archive is a collection of computer files that have been packaged together for backup, to transport to some other location, for saving away from the computer so that more hard disk storage can be made available, or for some other purpose. An archive can include a simple list of files or files organized under a directory or catalog structure (depending on how a particular program supports archiving).

ASCII

ASCII is the most common format for text files in computers and on the Internet. In an ASCII file, each alphabetic, numeric, or special character is represented with a 7-bit binary number (a string of seven 0s or 1s). 128 possible characters are defined.

UNIX and DOS-based operating systems (except for Windows NT) use ASCII for text files. Windows NT uses a newer code, Unicode. IBM's System 390 servers use a proprietary 8-bit code called EBCDIC. Conversion programs allow different operating systems to change a file from one code to another.

ASCII was developed by the American National Standards Institute (ANSI).

B

Binary Files

Computer files that are in a machine readable rather than human readable format.

Boolean Operators

"AND", "OR" and "NOT" used to describe logical relationships about or between terms, variables and statements. They can be used with terms in search queries to refine user search queries. To find documents on recycling other than paper you could enter the search:
recycling AND NOT paper

Browser

A browser is a program that provides a way to look at, read, and even hear all information on the World Wide Web. It uses the Hypertext Transfer Protocol (HTTP) to request a page from a Web site host computer, known as a server, and retrieves the requested page on behalf of the user. Web pages contain special instructions written in Hypertext Markup Language (HTML) that tell the browser how to display the document on the user's screen. Browsers interpret Web programming code differently depending on brand name and version number. Older browsers generally have less functionality than current versions. The two common browsers currently used on the Web are Netscape's Navigator and Microsoft's Internet Explorer. Both have their own distinguishing characteristics interpreting HTML code; however, current versions 4.0+ generally read Web programming code in similar fashion.

C

Cascading Style Sheets (CSS)

Cascading Style Sheets, or CSS, is a feature of HTML that gives both Web site developers and users more control over how Web pages are displayed. Developed by the W3C, CSS allows designers to create style sheets that define how different elements, such as headers and links, appear throughout an entire Web site.

Central Client Server Systems

Includes various UNIX and Windows NT computer systems, efficiently managed in a production environment. NCC manages and administers the systems and facilities supporting them, performing all systems management disciplines necessary to add value to the computational power of the servers themselves and provide a secure, reliable, and efficient computing platform for the accomplishment of the Agency's mission

Central Data Base Technical Support

Provides a wide variety of technical support to data base applications designers and developers on all platforms and data base management systems.

Client/Server

A distributed model of interaction in which a single application services requests from one or more other applications. The application handling the request is referred to as the server and the applications requesting services or information as the clients.

ColdFusion

ColdFusion is a database gateway application created by Macromedia that uses its own server-side code called ColdFusion Markup Language (CFML). CFML builds interactivity into Web pages by embedding direct links to databases and other content sources.

CGI (common gateway interface)

The common gateway interface (CGI) is a standard way for a Web server to pass a Web user's request to an application program and to receive data back to the user. When the user requests a Web page (for example, by clicking on a highlighted word or entering a Web site address), the server sends back the requested page. However, when a user fills out a form on a Web page and sends it in, it usually needs to be processed by an application program. The Web server typically passes the form information to a small application program that processes the data and may send back a confirmation message. This method or convention for passing data back and forth between the server and the application is called the common gateway interface (CGI). It is part of the Web's HTTP protocol.

Cookie

A cookie is a special text file that a Web site puts on your hard disk so that it can remember something about you at a later time. Typically, a cookie records your preferences when using a particular site. Using the Web's Hypertext Transfer Protocol (HTTP), each request for a Web page is independent of all other requests. For this reason, the Web page server has no memory of what pages it has sent to a user previously or anything about your previous visits. A cookie is a mechanism that allows the server to store its own file about a user on the user's own computer. The file is stored in a subdirectory of the browser directory (for example, as a subdirectory under the Netscape directory). The cookie subdirectory will contain a cookie file for each Web site you've been to that uses cookies.

Cookies are commonly used to rotate the banner ads that a site sends so that it doesn't keep sending the same ad as it sends you a succession of requested pages. They can also be used to customize the pages they send you based on your browser type or other information you may have provided the Web site. Web users must agree to let cookies be saved for them, but, in general, it helps Web sites to better serve users.

D

Database

A database is a collection of data that is organized so that its contents can easily be accessed, managed, and updated. The most prevalent type of database is the relational database, a tabular database in which data is defined so that it can be reorganized and accessed in a number of different ways. A distributed database is one that can be dispersed or replicated among different points in a network. An object-oriented database is one that is congruent with the data defined in object classes and subclasses.

Databases contain aggregations of data records or files, such as sales transactions, product catalogs and inventories, and customer profiles. Typically, a database manager provides users the capabilities of controlling read/write access, specifying report generation, and analyzing usage. Databases and database managers are prevalent in large mainframe systems, but are also present in smaller distributed workstation and mid-range systems such as the AS/400 and on personal computers. SQL is a standard language for making interactive queries from and updating a database such as IBM's DB2, Microsoft's Access, and database products from Oracle, Sybase, and Computer Associates.

DBSS

DataBase Systems Support group is a pool of resources that provides complete technical and consulting support in reference to database applications.

Development Server

A server utilized for the sole purpose of developing and testing an application before putting it into production.

E

EDI

Electronic data interchange is the computer-to-computer transfer of information using standard file transfer formats that may be used by all types of computers. EDI can be used to transfer many types of data, ranging from business documents to scientific data. EDI uses a standard electronic format, known as American National Standards Institute (ANSI) X12 format to enable otherwise incompatible computers to communicate. Within X12, "transaction sets" are created from routine sets of data, an electronic "envelope" is created, the data is put in the envelope, and the envelope is sent to the trading partner. The trading partner reverses the process, which results in data the receiver's computer system can process.

Environmental Data Registry (EDR)

The Environmental Data Registry (EDR), developed by the U.S. Environmental Protection Agency (EPA), is a comprehensive, authoritative source of reference information about environmental data. It is not the environmental data itself, but rather the information that helps describe the data and make it more meaningful. Just as EPA's Envirofacts serves as a clearinghouse for much of the Agency's environmental data, the EDR serves as the clearinghouse for information about the data. It provides information on the definition, origin, source, and location of environmental data. When used in conjunction with an environmental information database, the EDR enables users to better understand the information they are accessing. It also serves as a major tool to support a standard-setting process, to record and disseminate these standards, and ultimately to facilitate data sharing between organizations and users.

To learn more, start at the EPA EDR Page

Extranet

An extranet is a private network that uses the Internet protocols and the public telecommunication system to securely share part of a business's information or operations with suppliers, vendors, partners, customers, or other businesses. An extranet can be viewed as part of a company's intranet that is extended to users outside the company. It has also been described as a "state of mind" in which the Internet is perceived as a way to do business with other companies as well as to sell products to customers. The same benefits that HTML, HTTP, SMTP, and other Internet technologies have brought to the Internet and to corporate intranets now seem designed to accelerate business between businesses.
An extranet requires security and privacy. These require firewall server management, the issuance and use of digital certificates or similar means of user authentication, encryption of messages, and the use of virtual private networks (VPNs) that tunnel through the public network.

Extensible Markup Language (XML)

See XML.

F

FAQ

Frequently Asked Questions - these documents contain questions commonly asked on the specified topic and the answers associated with the questions.

Flash

Flash, a Macromedia plug-in, is a popular multimedia player for interactive vector graphics and animation for the Web. Web designers use Flash to create resizable and compact navigation interfaces, technical illustrations, long-form animations, and other effects. Another Macromedia muiltimedia player for use on the web is Shockwave.

FTP (File Transfer Protocol)

FTP (File Transfer Protocol), a standard protocol, is the simplest way to exchange files between computers on the Internet. Like the Hypertext Transfer Protocol (HTTP), which transfers displayable Web pages and related files, and the Simple Mail Transfer Protocol (SMTP), which transfers email, FTP is an application protocol that uses the Internet's TCP/IP protocols. FTP is commonly used to transfer Web page files from their creator to the computer that acts as their server for everyone on the Internet. It's also commonly used to download programs and other files to your computer from other servers.

As a user, you can use FTP with a simple command line interface (for example, from the Windows MS-DOS Prompt window) or with a commercial program that offers a graphical user interface. Your Web browser can also make FTP requests to download programs you select from a Web page. Using FTP, you can also update (delete, rename, move, and copy) files at a server. You need to log on to an FTP server. However, publicly available files are easily accessed using anonymous FTP.

FTP Client

The software that runs on a client (usually a desktop machine) that is used to connect to a server that is running FTP. See FTP above.

Frames

Frames are HTML tags (i.e., FRAMESET, FRAME) that create independently changeable windows that tile together to increase functionality and visual appeal of a Web site. They break up your browser's display window into individual, independent panes. Each frame holds its own HTML file as content, which can be scrolled or changed independently of the others.

G

Guidance

A non-mandatory compilation of advice, examples, best practices or past experience. Guidance supplements procedures.

H

Home Page

A home page is the entry point to a Web site. It is the first page of information received by a visitor. Although the term "home page" is commonly used as a synonym for "Web server" or "document collection", in this document the terms are not equivalent.

HTML

HyperText Markup Language (HTML) is a simple markup system used to create Web pages and is the backbone of the Internet. HTML is limited in its stylistic presentation of Web pages. Its focus is on the structure of a document rather than its appearance. Web developers sidestep HTML's limitations by using techniques such as advanced Web programming (DHTML, JavaScript, Java, ASP), to improve the presentation of their Web pages.

I

Image Map

In Web page development, an image map is a graphic image defined so that a user can click on different areas of the image and be linked to different destinations. You make an image map by defining each of the sensitive areas in terms of their X and Y coordinates (that is, a certain horizontal distance and a certain vertical distance from the left-hand corner of the image). With each set of coordinates, you specify a URL or Web address that will be linked to when the user clicks on that area.
The X and Y coordinates are expressed in pixels either in a separate file called a map file or in the same HTML file that contains the link to the image map. Popular tools like MapEdit provide a graphical interface for creating an image map (so that you don't have to figure out the X and Y coordinate numbers yourself).
Originally, the map file had to be sent to the server. Now the creator can place the map information either at the server or at the client (a "client-side map").

Internet

The Internet, often called simply the Net, is a worldwide system of linked computer networks. It provides millions of individuals, businesses and corporations, educational institutions, governmental agencies, and countries with the ability to electronically communicate and efficiently disseminate information over great distances. Today, the most popular applications of the Internet include electronic mail or email, file transfer, and the World Wide Web. The Internet is made possible through high-speed digital telephone lines. These high-bandwidth cables serve as the Internet's backbones. These cables comprise a handful of major networks which are in turn connected to smaller regional and local area networks around the world.

IP address (Internet Protocol address)

This definition is based on Internet Protocol Version 4. See Internet Protocol Version 6 (IPv6) for a description of the newer 128-bit IP address.)

In the most widely installed level of the Internet Protocol (IP) today, an IP address is a 32-bit number that identifies each sender or receiver of information that is sent in packets across the Internet. When you request an HTML page or send email, the Internet Protocol part of TCP/IP includes your IP address in the message (actually, in each of the packets if more than one is required) and sends it to the IP address that is obtained by looking up the domain name in the URL you requested or in the email address you're sending a note to. At the other end, the recipient can see the IP address of the Web page requester or the email sender and can respond by sending another message using the IP address it received.

An IP address has two parts: the identifier of a particular network on the Internet and an identifier of the particular device (which can be a server or a workstation) within that network. On the Internet itself - that is, between the routers that move packets from one point to another along the route - only the network part of the address is looked at.

IP Stack

Part of the behind the scenes software that allows a computer to connect and communicate through the Internet. In general it is a Protocol Stack.

Intranet

Specific to EPA, the Intranet consist of those servers that are available only to EPA and those designated outside "epa.gov" who have access. Because new equipment will have new names, we refer to "Intranet" and it's counterpart "Public Access" to represent the two realms of EPA information that is served in a Web environment. Below is a general description of an Intranet.

An intranet is a network of networks that is contained within an enterprise. It may consist of many interlinked local area networks and also use leased lines in the wide area network. Typically, an intranet includes connections through one or more gateway computers to the outside Internet. The main purpose of an intranet is to share company information and computing resources among employees. An intranet can also be used to facilitate working in groups and for teleconferences.

An intranet uses TCP/IP, HTTP, and other Internet protocols and in general looks like a private version of the Internet. With tunneling, companies can send private messages through the public network, using the public network with special encryption/decryption and other security safeguards to connect one part of their intranet to another.

Typically, larger enterprises allow users within their intranet to access the public Internet through firewall servers that have the ability to screen messages in both directions so that company security is maintained. When part of an intranet is made accessible to customers, partners, suppliers, or others outside the company, that part is called an extranet.

J

Java

A Java(TM) servlet is a Java(TM) program that runs within the context of a server, analogous to a Java(TM) applet that runs within the context of a Web browser. Servlets are easy to implement since they take advantage of the support provided by the Java-enabled Web Server (e.g. parsing HTTP requests, handling connections to Web clients). They are also efficient since they run as separate light weight threads of the Java-enabled Web Server process rather than as separate heavy weight processes (e.g. CGI programs). For more information on Java Servlets refer to the Agency's Java(TM) Servlet Documentation

or Sun's Java(TM) Servlet Technology page.

JavaScript

Initially developed by Netscape, JavaScript is a Web scripting language that extends the capabilities of basic HTML by producing content that changes in response to user actions. JavaScript is embedded into a Web page's HTML code, always remaining part of the HTML document to which it is attached. JavaScript can be used in a variety of ways to create special graphical effects, validate user survey forms, etc.

L

LAN

Local Area Network - a collection of devices connected together through network hardware and software within a limited geographic area ranging up to the size of a college campus. Often the geographic area covered is much smaller.

Light Directory Access Protocol (LDAP)

A client-server protocol for accessing a directory service. It was initially used as a front-end to X.500, but can also be used with stand-alone and other kinds of directory servers.

Link Checker

A link checker is a program that tests and reports on the validity of the hypertext links on the pages in a Web site. More advanced link checkers test links to other Web sites as well as links between pages on the same site. A link checker may be a separate program that specializes in this service or part of a larger program that provides a range of Web site publishing services.

Listserv

A listserv is a mailing list that is supported by a listserver program. Depending on the product, users can subscribe via email or through a web-enabled interface. The listserver will automatically add the name and distribute future email postings per their preferences to every subscriber.

Listserver

A listserver (mailing list server) is a program that handles subscription requests for a mailing list and distributes new messages, newsletters, or other postings from the list's members to the entire list of subscribers as they occur or are scheduled. (A list server should not be confused with a mail server, which handles incoming and outgoing email for Internet users.) Some listserver products such as Lyris ListManager also provide a web-enabled interface as well. This allows users to read and submit posts online. Owners may also manage their list online.

Log File

An access log file is a list of all the requests for individual files that people have requested from a Web site. These files will include the HTML files and their imbedded graphic images and any other associated files that get transmitted. The access log (sometimes referred to as the "raw data") can be analyzed and summarized by another program.

In general, an access log can be analyzed to tell you:

The number of visitors (unique first-time requests) to a home page
The origin of the visitors in terms of their associated server's domain name (for example, visitors from .edu, .com, and .gov sites and from the online services)
How many requests for each page at the site, which can be presented with the pages with most requests listed first
Usage patterns in terms of time of day, day of week, and seasonally

M

Metadata

A definition or description of data. In essence it's data about data, but at a higher, more general level. For instance, if a Web site/document contains specific data on water temperatures in the Potomac River, metadata data about this might be "water", "temperature", and "Potomac River".

Meta Tag

An HTML tag included in the HEAD section used to designate meta-information about the document such as author, revision date, keywords, or owner.

O

Organization

The Organization of Federal Agencies varies slightly. However, they are generally hierarchical in the fashion Agency, Office, Division, Branch, and Individual or Program or Project. Home pages intended to serve the Agency itself (i.e. internal servers) are probably best arranged in this hierarchical fashion. Home pages intended to serve the public are probably better arranged by area of public interest (e.g., mission, initiatives, etc.) with Organization as merely one topic.

Owner, Administrative

An individual with rights to administer an email list through the use of system commands sent to the list server. Administrative owners are list specific, and may post messages directly to moderated lists without needing approval. One administrative owner is considered the list owner who will receive all error message and approval requests. Please note, that all administrative owners can process those requests.

Owner, Federal

Each email list must have an EPA employee who requests and is ultimately responsible for the list.

Owner, List

See owner, administrative.

Owner, Silent

An individual with rights to post messages directly to a moderated list.

P

Page

A page is an individual computer file containing displayed information viewed in a Web browser which can be addressed by a hypertext link to and from other Web pages. Documents and collections (Web sites) are constructed of linked pages.

PERL - (Practical Extraction and Report Language

PERL is a programming language developed from the C programming language and inheriting many attributes from sed, awk, the UNIX shell and other useful tools. Its programming flexibility and strengths in text manipulation and database access have made it especially attractive for CGIdevelopment. For more information on the PERL language refer to the PERL.com

or the Comprehensive Perl Archive Network

PHP

PHP is an HTML-embedded scripting language. Much of its syntax is borrowed from C, Java and Perl with a couple of unique PHP-specific features thrown in. The goal of the language is to allow web developers to write dynamically generated pages quickly. The PHP web site provides an Introduction to PHP.

PL/SQL

PL/SQL stands for Procedural Language/ Source Query Language and is used in Oracle database applications. PL/SQL extends SQL by adding constructs found in procedural languages, resulting in a structural language that is more powerful than SQL. The basic unit in PL/SQL is a block. All PL/SQL programs are made up of blocks, which can be nested within each other. Typically, each block performs a logical action in he program.

Policy

A high-level statement about an Agency requirement designed to influence and determine decisions, actions, and other matters. It is usually driven by statute, Executive Order, the mandate of an oversight agency or Congress, or the head of the organization.

Port

A designation used to distinguish between different destinations within a given computer. The operating system will usually leave it to applications to specify the port it will be using with the exception of a number of standard ports reserved for various services such as email, FTP and web servers.

Portable Document Format (PDF)

PDF is a file format that preserves the printed appearance of a document as an electronic image that you can view, navigate, print, or forward to someone else. To view and use a PDF file requires a special external viewer program such as Adobe Acrobat Reader.

Procedure

The required steps, courses of action, or processes needed to accomplish or satisfy a policy.

Production Server

EPA uses a two tier segmentation of their servers. There are a set of staging servers and a set of development servers. This is to ensure against a major outage, slow down, or other mishap while new applications and Web sites are developed, and existing ones are improved. Once an application or Web site is finished in development, it is moved from any number of development servers to the corresponding production server.

Public Access

The servers that make up EPA's Internet presence. These servers contain and share information that is available for public consumption. Servers include epapub.epa.gov for regular HTML and yosemite.epa.gov for Notes/Domino access. The server names are not static and may change as new equipment is put in place, however the phrase "Public Access" and it's counterpart "Intranet" will remain in use.

Push

Push" (or "server-push") is the delivery of information on the Web that appears to be initiated by the information server rather than by the information user or client, as it usually is. The best known examples of the practice of "pushing" information rather than having it "pulled" as the result of requests for Web pages is Pointcast, a site that provides up-to-date news and other information tailored to a previously defined user profile. Marimba is a somewhat similar site (and product) that "pushes" information to the user according to a predefined schedule.

In fact, the information pushed from a server to a user actually comes as the result of a programmed request from the client in your computer. That is, Pointcast, Marimba, and similar information pushers require that you download a client program. This program captures your profile and then periodically initiates requests for information on your behalf from the server.

A truer form of push is broadcast information. In this case, the information is pushed to everyone that has access to a particular channel or frequency. Broadcast usually (but not always) involves a continuous flow of information.

R

Replication

Replication (pronounced rehp-lih-KA-shun) is the process of making a replica (a copy) of something. A replication (noun) is a copy. The term is used in fields as varied as microbiology (cell replication), knitwear (replication of knitting patterns), and information distribution (CD-ROM replication).

On the Internet, a Web site that has been replicated in its entirety and put on another site is called a mirror site.

Using the groupware product, Lotus Notes, replication is the periodic electronic refreshing (copying) of a database from one computer server to another so that all users in the Notes network constantly share the same level of information.

S

Search Engine

On the Internet, a search engine has three parts:

A spider (also called a "crawler" or a "bot") that goes to every page or representative pages on every Web site that wants to be searchable and reads it, using hypertext links on each page to discover and read a site's other pages
A program that creates a huge index (sometimes called a "catalog") from the pages that have been read
A program that receives your search request, compares it to the entries in the index, and returns results to you

An alternative to using a search engine is to explore a structured directory of topics. Yahoo, which also lets you use its search engine, is the most widely-used directory on the Web. A number of Web portal sites offer both the search engine and directory approaches to finding information.

There are about eight major Web sites with their own search engines (although some have an arrangement to use another site's search engine). Some sites, such as Yahoo, search not only using their search engine but also give you the results from simultaneous searches of other search indexes.

Sites that let you search multiple indexes simultaneously include:

Yahoo (http://www.yahoo.com)
search.com (http://search.com)
EasySearcher (http://www.easysearcher.com)

Yahoo first searches its own hierarchically-structured subject directory and gives you those entries. Then, it provides a few entries from the Alta Vista search engine. It also launches a concurrent search for entries matching your search argument with six or seven other major search engines. You can link to each of them from Yahoo (at the bottom of the search result page) to see what the results were from each of these search engines.

The major search engines on the Web are:

Google (http://www.google.com)
Alta Vista (http://www.altavista.digital.com)
Excite (http://www.excite.com)
Hotbot (http://www.hotbot.com)
Infoseek (http://www.infoseek.com)
Lycos (http://www.lycos.com)
WebCrawler (http://www.webcrawler.com)

SSL (Secure Sockets Layer)

SSL (Secure Sockets Layer) is a program layer created by Netscape for managing the security of message transmissions in a network. The idea is that the programming for keeping your messages confidential ought to be contained in a program layer between an application (such as your Web browser or HTTP) and the Internet's TCP/IP layers. The "sockets" part of the term refers to the sockets method of passing data back and forth between a client and a server program in a network or between program layers in the same computer. Netscape's SSL uses the public-and-private key encryption system from RSA, which also includes the use of a digital certificate.

Shareware

Shareware is software that is distributed free on a trial basis with the understanding that the user may need or want to pay for it later. Some software developers offer a shareware version of their program with a built-in expiration date (after 30 days, the user can no longer get access to the program). Other shareware (sometimes called liteware) is offered with certain capabilities disabled as an enticement to buy the complete version of the program. Freeware is programming that is offered at no cost. However, it is copyrighted so that you can't incorporate its programming into anything you may be developing. The least restrictive "no-cost" programs are uncopyrighted programs in the public domain. These include a number of small UNIX programs. When reusing public domain software in your own programs, it's good to know the history of the program so that you can be sure it really is in the public domain.

Shockwave

Similar to Flash, Shockwave is multimedia player developed by Macromedia, an Internet services company. Web users with Windows and Mac platforms can download the Shockwave players from the Macromedia Web site and use it to display and hear Shockwave files that can include sound, animation, and video. To create Shockwave files, you must use Director, Macromedia's popular software program used to create 3D graphics and animation, plus several other related Macromedia programs.

T

Telnet

Telnet is the way you can access someone else's computer, assuming they have given you permission. (Such a computer is frequently called a host computer.) More technically, Telnet is a user command and an underlying TCP/IP protocol for accessing remote computers. The Web or HTTP protocol and the FTP protocol allow you to request specific files from remote computers, but not to actually be logged on as a user of that computer. With Telnet, you log on as a regular user with whatever privileges you may have been granted to the specific applications and data on that computer.

Technical Contacts

A point-of-contact person assigned to provide assistance to the application developers throughout the entire application development, review, deployment and maintenance stages. For a more detailed description of services provided, see the WCF Services

page.

Telnet Client

The software that runs on a client (usually a desktop machine) that is used to connect to a server that is running Telnet. See Telnetabove.

Thumbnail Pictures

A thumbnail picture is a small version of a larger graphic. The typical size of these pictures is often in the range of 40 by 60 pixels. These pictures are placed within documents to provide the customer with a general idea of the picture. Often a thumbnail is used as an anchor to a full-sized version of the graphic.

TSSMS

Time Sharing System Management System (TSSMS) is the user control system used to manage accounts, among other things on the EPA servers.

TCP/IP (Transmission Control Protocol/Internet Protocol)

TCP/IP (Transmission Control Protocol/Internet Protocol) is the basic communication language or protocol of the Internet. It can also be used as a communications protocol in the private networks called intranets and in extranets. When you are set up with direct access to the Internet, your computer is provided with a copy of the TCP/IP program just as every other computer that you may send messages to or get information from also has a copy of TCP/IP.

TCP/IP is a two-layered program. The higher layer, Transmission Control Protocol, manages the assembling of a message or file into smaller packets that are transmitted over the Internet and received by a TCP layer that reassembles the packets into the original message. The lower layer, Internet Protocol, handles the address part of each packet so that it gets to the right destination. Each gateway computer on the network checks this address to see where to forward the message. Even though some packets from the same message are routed differently than others, they'll be reassembled at the destination.

U

UNIX

Most commonly used to refer to a category of operating systems based on the operating system of the same name created at Bell Laboratories. UNIX operating systems share many common characteristics including being multi-user, multitasking and command line oriented.

Uniform Resource Locator (URL)

A Uniform Resource Locator is the address of an Internet file which includes the service protocol or IP address, the registered domain name, the directory path, and the data file name.

W

Web Clients

Software applications, typically browsers, that access information which is typically distributed over the Internet.

Web Information Service

A home page and linked subordinate content, whether on the same server or other Internet sites. A Web information service does not necessarily have to comprise a single document or document collection. A Web information service does not have to be a static document or text. A Web information service may, for example, be a database accessed by one or more forms or text indexes.

Web Server

A World Wide Web Server is a computer which provides access to one or more collections of documents using World Wide Web formats and protocols. Each WWW Server has a main entry point or IP address; however, numerous Web sites can be hosted based on directory location and are usually addressed directly through a registered domain name.

Webmaster

Each Web server has a Webmaster -- an individual with primary responsibility for the server. By convention, each Web server maintains a Webmaster email address (e.g., webmaster@www.navsea.navy.mil) to which suggestions and inquiries about the site may be directed.

Working Capital Fund (WCF)

The Working Capital Fund (WCF) is an intra-governmental revolving fund of working capital authorized by law to finance a cycle of operations (namely, client support, technology integration, and client communications) where the costs of goods and services provided are charged to the users on a fee-for-services basis.

World Wide Web

The World Wide Web is a global network document publishing system that uses HTML and other Web programming languages to disseminate information on all topics and subject areas.

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XHTML

XHTML is an XML document type developed by the World Wide Web Consortium as the successor to HTML. XHTML consists of the elements of HTML, restricted such that documents conform to the rules of XML. XHTML tags are assigned the same meaning by browsers as the corresponding HTML tags, hence XHTML documents, unlike ordinary XML documents, can be formatted for display without external formatting information.

XML

XML is the Extensible Markup Language. It is writen in Standard Generalized Markup Language (SGML), the international standard metalanguage for text markup systems (ISO 8879). XML can be used to describe customized markups for any type of document because, unlike other SGML-derived markup languages, such as HTML, it is not comprised of a fixed vocabulary of document elements. XML itself is a meta-language used to develop markup languages that describe the content and structure, but not the presentation, of documents.

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