In response to the call to serve from the Vatican II Council (1962-1965), the laity has stepped up to serve parishes and the Church in different ways: catechetical ministry, liturgical ministries, advisory councils, social justice, pastoral and social outreach, etc.
The groundwork for this involvement was laid mostly in the 1920s by Catholic Action, a movement of the laity's active work in the fields of dogma, morals, liturgy, education, and charity. It included general Catholic Action groups open to all Catholics, such as the Holy Name Society and the Legion of Mary (Legio Mariae); and specialized Catholic Action organizations for professions or interest groups, such as workers, doctors, lawyers, students, or married couples.
Catholic Action was conceived as an extension of the church hierarchy (bishops, priests, deacons). It became clear in 1927 when Pope Pius XI described Catholic Action as “the participation of the laity in the apostolate of the hierarchy.”
Eventually, there's a growing awareness of the broader notion of the lay apostolate, which encourages the laity to autonomously bring a Christian influence to the temporal society. In other words, it's a call to evangelization. By the time of the Vatican II Council, this idea became more evident and formally recognized by the Church.
The Council emphasized the responsibility of the laity in its dogmatic constitution on the Church "Lumen gentium" (1964), chapter 4 on "The Laity" (nos. 30-38); and on the decree "Apostolicam actuositatem" on the Apostolate of the Laity (1965).
However, in the post-Vatican II period, the notion of the apostolate of the laity has been largely replaced by the all-purpose term "ministry" (from Latin "ministerium," meaning office, service). Ministry now denotes virtually any service of lay persons inside or outside the parish.