A church can have one single nave or a vaisseau central (central nave) with two or more bas-côtés (aisles, they are also part of the nave).
The axis of the nave coincides with the east-west axis of the church.
In plan the nave is indicated in pink.
In the picture the nave and two aisles of the Saint-Martin in Chapaize.
See also nef (synonym).
|Vaisseau - Wikipedia|
|Saint-Martin - Chapaize|