A more thorough explanation:

A sex-offender registry is a public list of the names and addresses of individuals who have been convicted of sex crimes and released from prison. These registries were established by state laws known as "Megan's laws," which require sex offenders to register with a local board and provide information about their whereabouts to the community.

The purpose of these registries is to help protect the public from potential harm by providing information about convicted sex offenders who live in their area. Some states require the publication of the offender's photograph, name, and address in local newspapers, and many of these lists are also available online.

For example, if a person moves into a new neighborhood and wants to know if there are any registered sex offenders living nearby, they can search the sex-offender registry to find out. This information can help them make informed decisions about their safety and the safety of their family.