Key takeaways:

• Jails are generally local facilities used for short-term detention and are commonly operated by county or municipal authorities.
• Jails hold many people awaiting trial or other court proceedings, as well as some people serving shorter sentences.
• Prisons are generally state or federal facilities for people convicted of crimes and serving longer sentences.
• A sentence of about one year is a common shorthand for distinguishing jail from prison incarceration, but it is not a universal rule.

How are jails and prisons different?

Although “jail” and “prison” are often used interchangeably, they are different types of facilities with different purposes.

• Jails are usually operated by local governments and hold people awaiting trial or serving shorter sentences, generally up to a year.
• Prisons are run by state or federal governments and hold people serving longer sentences after they have been convicted.

Who operates prisons and jails? Jails are commonly operated by county or municipal authorities, while prisons are generally run by state or federal governments.

What is a jail?

A jail is a short-term detention facility operated by a county or city. It may hold people convicted of lower-level offenses and those serving shorter sentences, often less than a year. Jail practices and sentence limits vary by state and local jurisdiction. Most people in jail have not been convicted of a crime. Many are held before trial because they cannot afford bail, leaving them in jail detention while they wait for their day in court—which may be weeks or months away.

In 2024, the 3,116 local jails scattered across the country held about 662,100 people on any given day. But that already staggering number pales in comparison to the millions of people admitted to jail every year—more than 7.6 million jail admissions were reported in 2023. Data journalist and illustrator Mona Chalabi helps visualize what exactly that looks like in her work for the Prison Policy Initiative.

Roughly 74 percent of arrests that could land people in jail are for low-level misdemeanor offenses, like disorderly conduct and drug abuse. Less than 5 percent of arrests are for violent offenses.

Hundreds of thousands of people are detained in jails every year solely because they’re unable to pay bail. It’s one way our criminal justice system criminalizes people experiencing poverty and homelessness.

In the worst cases, people have died while waiting for their day in court. Jails are typically meant to serve as short-term detention facilities, but there are many devastating exceptions. Since 2025, 22 people have died in New York City jails, many of them while they were at Rikers Island, the country’s most notorious jail complex and the city’s largest. Rikers has been described as “a torture chamber.”

What is a prison?

Prisons are long-term detention facilities, holding people serving sentences to incarceration longer than a year—usually much longer because the United States sends people to prison for extraordinarily long periods of time. About 1.3 million people are currently incarcerated in state and federal prisons operated by state departments of corrections or the Federal Bureau of Prisons. The Sentencing Project found, for example, that as of 2024, one in six people—or nearly 200,000 people—in U.S. prisons was serving a life sentence. That is roughly the country’s entire incarcerated population in 1970.

Changes in sentencing law and policy help explain this astronomical rise. “Tough-on-crime” legislation, beginning in the 1970s and culminating with the 1994 Violent Crime Control and Law Enforcement Act, gave rise to overly punitive sentencing legislation at the state and federal levels. A spate of sentencing laws—such as mandatory minimums, “three-strikes” and other “habitual offender” laws, and life without parole sentences—helped fuel mass incarceration, as the country’s incarceration rate more than tripled from 1971 to 1999.

Curtis Wilkerson is one of the many people sentenced during this time under California’s “three-strikes” law. He was sentenced to 25 years to life. His crime? Stealing a pair of socks.

What do jails and prisons have in common?

People in both jails and prisons face cruel and abusive conditions—violence; overcrowding; wholly inadequate health care; unhealthy, processed foods; freezing and sweltering temperatures; and rules that make it almost impossible to stay connected to loved ones.

The United States pours hundreds of billions in taxpayer dollars into these facilities. But incarceration doesn’t make our communities safer.

Instead, even a single day behind bars can make it difficult for people to keep their jobs or pay rent, making it hard for them to provide for their families. Studies show that jail is so destabilizing to people’s lives that it makes it more likely they will be arrested again in the future.

Moreover, a conviction—even for a minor offense—can have lasting and detrimental effects, called “collateral consequences.” These include barriers to accessing education, securing housing, and finding employment. In fact, research shows that a conviction can lead to a lifetime of lower wages.

The criminal justice system’s impact is sweeping. Between 70 million and 100 million people in the United States—about one in three adults—have an arrest or conviction record. And, because of the racial bias inherent in and embedded within every aspect of our criminal justice system, Black people are more likely to be stopped, searched, arrested, and sentenced more harshly than white people.

Ninety-five percent of people in prison will eventually return to their communities. Instead of enabling their success, the U.S. criminal justice system mounts barriers that make this transition needlessly difficult. This system prioritizes punishment, not safety and well-being. And its focus, to date, on building out the infrastructure to incarcerate has actually undermined public safety.

Local, state, and federal governments must redirect the billions spent on mass incarceration into things that support a “serious about safety” policy agenda. Our leaders should channel those funds toward evidence-based solutions that make us safer: investments in education, health, housing, jobs, and transportation.