The Angelus commemorates the Incarnation three times daily - at 6 AM, noon, and 6 PM - when church bells traditionally ring. It recalls the Angel Gabriel's announcement to Mary and her "yes" that changed the world.
The Angelus
V. The Angel of the Lord declared unto Mary,
R. And she conceived of the Holy Spirit.
Hail Mary...
V. Behold the handmaid of the Lord,
R. Be it done unto me according to thy word.
Hail Mary...
V. And the Word was made flesh,
R. And dwelt among us.
Hail Mary...
V. Pray for us, O holy Mother of God,
R. That we may be made worthy of the promises of Christ.
Let us pray:
Pour forth, we beseech thee, O Lord, thy grace into our hearts,
that we to whom the Incarnation of Christ thy Son
was made known by the message of an angel,
may by his Passion and Cross
be brought to the glory of his Resurrection.
Through the same Christ our Lord.
Amen.
Note: During the Easter season (from Easter Sunday through Pentecost), the Regina Caeli replaces the Angelus.