Final answer:
The statement is true; an apse is indeed a semi-circular area located at the end of a church's main aisle, or nave, and often holds significant religious importance.
Step-by-step explanation:
An apse is an architectural feature found at the end of the nave within a church, often taking a semi-circular shape covered with a hemispherical vault. The statement that an apse is a semi-circular area at the end of the long center aisle of a church is true.
Building on the design of the Roman basilica, Christian churches frequently feature an apse at the eastern end, opposite the main entrance. This structure often holds significant symbolic and functional roles, including serving as the location for the altar and housing important religious imagery such as mosaics or frescoes depicting holy figures.
Churches might also include a transept, which runs perpendicular to the nave, giving the building a cruciform shape reminiscent of the Crucifixion. In certain architectural styles, like that of the Eastern (Byzantine) Empire, the focus might shift to a more centrally planned design, where an apse can be part of that complex structure.
The church of San Vitale in Ravenna is an archetype of such centrally planned churches, demonstrating a departure from the traditional basilica layout that places a prominent apse at one end of the nave.