The Olympics are a prestigious series of athletic competitions held once every two years. Athletes from around the world train for years to make it to the Olympics.
Olympics is shorthand for the Olympic Games, which take place in a different city every two years. The Summer Olympics alternate with the Winter Olympics, so if your favorite sport is volleyball, you have to wait four years between Olympic-level competition. This multi-sport event originated in the 8th century BCE and took place in the district of Olympia, where there was a temple to Zeus. Ancient Greek athletes played there in honor of the god of thunder.