While each architectural era has its distinctive features, there are some elements, floor plans, and terms common to many. This is particularly true of churches, large numbers of which were built in Europe from the Middle Ages through the 18th century.

From the Norman period on, most churches consist either of a single, wide aisle, or a wide central nave flanked by two narrower aisles. The aisles are separated from the nave by a row of columns, or square stacks of masonry called piers, connected by arches. Sometimes--especially in the medieval Norman and Gothic eras--there is a second level to the nave, above these arches (and hence above the low roof over the aisles) punctuated by windows called a clerestory.

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 crucifix). The shorter, east arm of the nave is called the chancel; it often houses the altar and stalls of the choir. Some churches use a rood screen (so called because it supports a rood, the Saxon word for crucifixion) to separate the nave from the chancel. If the far end of the chancel is rounded off, we call it an apse. An ambulatory is a curving corridor outside the altar and choir area, separating it from the ring of smaller chapels radiating off the chancel and apse.

Some churches, especially after the Renaissance when mathematical proportion became important, were built on a Greek Cross plan, with each axis the same length like a giant plus sign ("+").

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