The Lord leads all persons by paths and in ways pleasing to him, and each believer responds according to his heart's resolve and the personal expressions of his prayer. However, Christian Tradition has retained three major expressions of prayer: vocal meditative, and contemplative. They have one basic trait in common: composure of heart. This vigilance in keeping the Word and dwelling in the presence of God makes these three expressions intense times in the life of prayer.
Source: Catechism of the Catholic Church (Vatican.va)