What’s the difference between jail and prison?
Jails (sometimes called community correctional centers) are short-term lockups normally run by counties and staffed by county sheriffs. Defendants housed in jails include those awaiting trial and unable to make bail, those serving sentences for misdemeanor offenses, and those felons who have to do jail time as a condition of probation. Because jails are devoted to short-term incarceration, they typically lack many of the facilities and programs that are sometimes available in prisons, such as libraries and exercise areas.
Prisons (also called penitentiaries and, in slang, “the joint,” “the pen,” “the big house,” or “up the river”) are normally operated by the federal and state governments, and their purpose is long-term incarceration. Most prison inmates serve sentences well in excess of a year. (See Prisoners' Rights.)
by: Paul Bergman