While each architectural era has its distinctive features, there are some elements, general floor plans, and terms common to many.

From the Romanesque period on, most churches consist either of a single wide aisle, or a wide central nave flanked by two narrow aisles. A row of columns, or square stacks of masonry called piers, connected by arches, separates the aisles from the nave.

This main nave/aisle assemblage is usually crossed by a perpendicular corridor called a transept near the far, east end of the church so that the floor plan looks like a Latin cross (shaped like a lowercase "t"). At the east end sits the holy altar. This is usually on a raised dais and in the entrance to -- or, especially later, just in front of -- the large chapel formed by the shorter, far end of the cross. If this large, main chapel is rounded off on the end, it is called an apse; it is often elongated and filled with the stalls of the choir. Some churches, especially after the Renaissance when mathematical proportion became important, were built on a Greek cross plan, each axis the same length, like a giant "+."

It's worth pointing out that very few buildings (especially churches) were built in one particular style. These massive, expensive structures often took centuries to complete, during which time tastes would change and plans would be altered.