In Brief CCC 777
© Libreria Editrice Vaticana Source: vatican.va
The word "Church" means "convocation." It designates the assembly of those whom God's Word "convokes," i.e., gathers together to form the People of God, and who themselves, nourished with the Body of Christ, become the Body of Christ.
Read the full chapter 3. I Believe in the Holy Spirit ¶683–1065