What distinguishes ancient Roman buildings from ancient Greek ones?

The ancient Greeks and Romans became famous for their architecture, which has a very similar style and impresses with its scale (temples, theaters). The Greeks and Romans decorated their architectural ensembles with a large number of columns and arches. However, the ancient Romans preferred to build circular buildings with a dome on top (Pantheon), with an abundance of arches (Aqueduct), and richly decorated columns (bas-reliefs, statues). The Greeks preferred square-shaped buildings, and used the mountainous terrain to equip theaters.