In A Nutshell
Even though the terms are often used interchangeably, prisons and jails are very different entities. A jail is used for short-term imprisonment, and is usually run by local law enforcement such as sheriffs. A prison is used for long-term imprisonment and is run by the state or federal government.
The Whole Bushel
A jail is run by county or city governments and is responsible for detaining those who are accused of a crime and unable to make bail, or those who are serving a relatively short sentence. While this varies by area and by jail, most jails are used only for people who are serving a sentence of less than a year. The majority of people housed in a jail—up to 85 percent—are released after only five days.
Prisons, on the other hand, are run by state or federal governments. Once a person is convicted of a crime and gets a long-term sentence handed down, they will be transferred to a prison to serve their time.
There are also different programs associated with each facility by extension. Jails are also responsible for running work-release programs for their occupants, as well as programs to manage substance abuse. Jails usually have some sort of vocational programs as well.
Since prisons are a much more long-term facility, their programs can be long-term as well. These can include basic to college education programs, technical education programs, behavior therapy, and seminars on making the transition from prison to the outside world. Prisons also run halfway houses, community restitution centers, and work-release programs; these programs are generally for inmates reaching the end of their prison terms.
Jails are often much smaller than prisons, with two-thirds of all jails in the United States responsible for less than 100 people on any given day.
Because of the higher turnover rate in jails, a jail environment tends to be much more chaotic than a prison environment. With inmates serving long sentences, daily life can be more structured and regimented than days in a jail. This leads to jails being more dangerous than prisons in many respects. In jails, inmates might not have had a thorough mental and physical exam, and they also may be less able to cope with incarceration; this can lead to a whole host of problems facing those running the jail.
Jails also have fewer daily activities than prison, which in turn adds to how dangerous they can be. People with little or nothing to do can be more prone to violence against others and themselves.
Funding sources for jail and prisons—along with their programs—are also different. Prisons receive their funding from the state and federal governments, which means they have a much wider source of funds. Because jails are funded by their county governments, there is a much smaller resource base and jails must fight harder for the resources they do receive.
A similar problem occurs in legal representation. When inmates and the accused rely on jails and prisons to provide legal counsel, there’s a definite difference in the type of representation a person is going to get. Prisons have lawyers and legal staff that are well versed in all aspects of criminal and civil law and have a much wider pool of attorneys to choose from. Jails rely on county counsels. Not only are there fewer attorneys to choose from, but because they handle such a wide variety of cases and issues, it’s more difficult to find someone who has a specific skill or knowledge set that might be needed.