A more thorough explanation:

A free chapel is a type of church that was founded by the Crown or a person under royal grant and is not subject to the jurisdiction of the bishop. This means that the bishop does not have authority over the church.

For example, a free chapel may be founded by the King and exempted from the bishop's jurisdiction. Alternatively, the King may grant a license to a subject to found a free chapel and exempt it from the bishop's visitation as well.

The term "free" refers to the exemption from the bishop's jurisdiction. This type of church was common in England during the medieval period.