A more thorough explanation:

The Uniform Mandatory Disposition of Detainers Act is a law that requires a state to promptly resolve any pending charges against a prisoner upon the prisoner's written request. This law was first introduced in 1958 and has been adopted by several states.

The Interstate Agreement on Detainers Act is a law that allows a state to obtain custody of a prisoner for trial, even if the prisoner is already incarcerated in another state. This law was first enacted in 1956 and applies to the federal government, certain states, and the District of Columbia.

Under this law, if a prisoner requests a disposition of the charges in the second state, the second state must try the prisoner within 180 days of the request. This law helps to ensure that prisoners are not held indefinitely without trial and that justice is served in a timely manner.

For example, if a prisoner is being held in California but has pending charges in Nevada, they can request a disposition of those charges under the Interstate Agreement on Detainers Act. If the request is granted, Nevada must try the prisoner within 180 days of the request.

This law helps to prevent prisoners from being held in limbo and ensures that they receive a fair and speedy trial. It also helps to reduce the burden on the criminal justice system by ensuring that cases are resolved in a timely manner.