The nave is the main space in the church. It is where the congregation sits. It runs from the western end of the church as far as the rood screen, or the step representing the start of the chancel or sanctuary.
The word nave comes from the Latin meaning 'ship' and may have been used because the roof of the nave, with its curving beams, reminded people of the hull of a ship.
An aisle lies to one side of the nave and is separated from it by a row of columns and arches. You only find aisles in larger churches when the builders wanted to make room for more people to get into the church. The altar ends of some aisles are used as chapels.