The Catechumenate (RCIA) is the normal way in which adults and children of school age become full, active participating members of the Catholic Church. Children and teens follow a process similar to the adults but adapted for their own peer group.
Many persons who want to join the Catholic Church have already been baptized in another Christian Church. They will not be rebaptized. The Christian Initiation journey will be adapted to fit the particular needs of Christians from another faith tradition.