Our English word church, like the German word "kirche", comes from the Greek for "house of the Lord". In French the word "Église" comes from the Latin word "ecclesia", which in turn comes from the Greek word for "assembly of the people", which in turn came from the Hebrew word for the "gathering of the people" by Moses in front of the presence of God on Mount Horeb, where God gave to the people the Ten Commandments. The building has the same name as the people: "the assembly of the people of God."
This is the elevated place where God makes himself at home with his people. In Jesus God has revealed his will and pleasure to dwell within us as in a temple. At Baptism, we are made temples of God's holy indwelling, temples of the Holy Spirit. On Sunday God gathers us together as his people in whom He dwells, and he makes this place a common dwelling or meeting place, where He speaks to our hearts, forgives our sins, heals our wounds or illness, gives us new life, strengthens us with the Bread of Life and Cup of Salvation, makes us his disciples, blesses our marriages and families, teaches us and brings us into the whole truth, and sends us out into the world to proclaim the Good News of his love to the whole world.
Below is a schematic map of the church. Click on the numbers on the map or use the corresponding list on the right to learn more about items of interest. (Also of interest, a paper by Julie Mancini on the architecture of the church can be found at this link.)