A more thorough explanation:

The Bureau of Prisons is a unit within the U.S. Department of Justice that is responsible for managing the federal prison system.

This means that the Bureau of Prisons oversees all federal prisons and correctional facilities, and helps states and local governments improve their own correctional facilities.

The Bureau of Prisons also provides notice of prisoner releases.

For example, if someone is serving time in a federal prison, the Bureau of Prisons is in charge of making sure they are housed and cared for while they are incarcerated.

Additionally, if a state or local government needs help improving their own correctional facilities, the Bureau of Prisons can provide assistance and guidance.

Finally, if a prisoner is going to be released from a federal prison, the Bureau of Prisons is responsible for notifying the appropriate parties.