Understanding the system
Jail vs. Prison: What's the Difference?
People use "jail" and "prison" interchangeably, but they are run by different authorities and hold different populations. Knowing the difference helps you search in the right place.
Last updated 4 min read
What a jail is
A jail is a local, short-term facility, usually operated by a county sheriff's office or a city. Jails hold people who have just been arrested and are awaiting their first court appearance, defendants who could not post bond while their cases are pending, and individuals serving shorter sentences — typically under a year. The population turns over constantly.
What a prison is
A prison is a longer-term facility run by a state department of corrections or the Federal Bureau of Prisons. Prisons hold people who have already been convicted of a crime and sentenced to longer terms, generally more than a year. Someone moves from jail to prison only after conviction and sentencing.
Why the difference matters when searching
Because jails and prisons are run by different authorities, they keep entirely separate records systems. A county jail roster will not show someone held in state prison, and a state inmate locator will not show someone sitting in a county jail awaiting trial.
If your search of a county roster comes up empty and you know the person was convicted and sentenced some time ago, they may have been transferred to a state or federal facility. In that case, you will need the relevant state department of corrections inmate locator or the Federal Bureau of Prisons locator instead.
The quick version
- Jail — local, short-term, run by a county or city; pretrial detainees and short sentences.
- Prison — state or federal, long-term, for people already convicted and sentenced.
- Different systems — each keeps separate records, so search the right one.