The second Vatican Council restored for the Latin Church “the catechumenate for adults, comprising several distinct steps.” The rites for these stages are to be found in the Rite of Christian Initiation of Adults (RCIA). The Council also gives permission that: “In mission countries, in addition to what is furnished by the Christian tradition, those elements of initiation rites may be admitted which are already in use among some peoples insofar as they can be adapted to the Christian ritual.”
Today in all the rites, Latin and Eastern, the Christian initiation of adults begins with their entry into the catechumenate and reaches its culmination in a single celebration of the three sacraments of initiation: Baptism, Confirmation, and the Eucharist. In the Eastern rites the Christian initiation of infants also begins with Baptism followed immediately by Confirmation and the Eucharist, while in the Roman rite it is followed by years of catechesis before being completed later by Confirmation and the Eucharist, the summit of their Christian initiation. – Catechism of the Catholic Church 1232-1233