The Rite of Christian Initiation of Adults takes place step by step in the midst of the Catholic community. The process itself has four periods.
The first period, the pre-catechumenate, is a time of inquiry on the part of the candidate and on the part of the Church. In this period, candidates have the Gospel preached to them so they can learn more about Jesus. It is a time of loose association with the Church when the candidates have no rights, privileges, or duties. Once they make their decision to follow Jesus as members of the Catholic community and then go through the Rite of Catechumens, they become catechumens.
The second period, the catechumenate, admits the person into the Church, which can last for several years. This period includes catechesis, or learning about the Catholic faith, and discovering what life as a Catholic is all about. It is completed on the Day of Election when the third period begins.
The third period - shorter in length and called enlightenment or purification - is a time of more profound spiritual preparation - purification and enlightenment or "illumination." It usually coincides with the Lenten season. After the Rite of Election, presided over by the bishop, the former catechumens are known as the elect. Together with the Catholic community, the elect decide whether or not they are ready for baptism. If the preparation seems adequate, the elect receive Baptism, Confirmation, and Eucharist, the sacrament of full initiation.
The final period, known as mystagogia or postbaptismal catechesis, is a time of deepening the Catholic experience. The new members continue to receive the sacraments and begin to participate fully in the life of the community.