Probation refers to adult offenders whom courts place on supervision in the community through a probation agency, generally in lieu of incarceration. However, some jurisdictions do sentence probationers to a combined short-term incarceration sentence immediately followed by probation, which is referred to as a split sentence. Probations can have a number of different supervision statuses including active supervision, which means they are required to regularly report to a probation authority in person, by mail, or by telephone. Some probationers may be on an inactive status which means they are excluded from regularly reporting, and that could be due to a number of reasons. For instance, some probationers may be placed on inactive status immediately because the severity of the offense was minimal or some may receive a reduction in supervision and therefore may be moved from an active to inactive status. Other supervision statuses include probationers who only have financial conditions remaining, have absconded, or who have active warrants. In many instances, while on probation, offenders are required to fulfill certain conditions of their supervision (e.g., payment of fines, fees or court costs, participation in treatment programs) and adhere to specific rules of conduct while in the community. Failure to comply with any conditions can result in incarceration.

Parole refers to criminal offenders who are conditionally released from prison to serve the remaining portion of their sentence in the community. Prisoners may be released to parole either by a parole board decision (discretionary release/discretionary parole) or according to provisions of a statute (mandatory release/mandatory parole). This definition of parole is not restricted to only prisoners who are released through a parole board decision, but also includes prisoners who are released based on provisions of a statute. Parolees can have a number of different supervision statuses including active supervision, which means they are required to regularly report to a parole authority in person, by mail, or by telephone. Some parolees may be on an inactive status which means they are excluded from regularly reporting, and that could be due to a number of reasons. For instance, some may receive a reduction in supervision, possibly due to compliance or meeting all required conditions before the parole sentence terminates, and therefore may be moved from an active to inactive status. Other supervision statues include parolees who only have financial conditions remaining, have absconded, or who have active warrants. Parolees are also typically required to fulfill certain conditions and adhere to specific rules of conduct while in the community. Failure to comply with any of the conditions can result in a return to incarceration.

Link to most recent probation and parole counts: Probation and Parole in the United States, 2007 - Statistical Tables