Evening Prayer (also called Vespers) is part of the Liturgy of the Hours, also known as the Divine Office. In the Liturgy of the Hours, the Church fulfills Jesus’ command to “pray always” (Luke 18:1; see also 1 Thessalonians 5:17). Through this prayer, the people of God sanctify the day by continual praise of God and prayers of intercession for the needs of the world.
For more information about Evening Prayer, please visit the USCCB website: Evening Prayer (Vespers) | USCCB