A base station is made up of several elements:
Designed to send and receive radio waves. Usually fixed to a support structure which is known as a mast.
May be tall and standalone (sometimes in rural areas), or smaller on the top of a tall building (often in urban areas). In some places masts are called towers.
Each base station has a cabinet with equipment to provide the power.
A mobile network is made up of many base stations that each provide coverage in its surrounding area.