What does being confirmed mean?

The religion of Roman Catholicism has a ritual called confirmation which is performed at the age of 13 (much like a Jewish bar mitzvah) and the purpose is to give the 13 year old child the opportunity to confirm, or verify, the he or she is indeed a Catholic. You don't just get born into Catholicism, you choose to be a Catholic, and this is the usual ritual by which it is done.