Greco-Roman and Freestyle wrestling were first introduced as a modern Olympic Games event in 1896. Both involve grappling. But there's a key difference. In Greco-Roman, wrestlers aren't allowed to grapple below the waist. And, only men participate in the Greco-Roman events. The wrestlers, in Greco-Roman, are scored based on their performance in two three-minute periods. But, an early 'fall' can terminate the round.
Only four countries — Germany, Great Britain, Greece and Hungary — were a part of the 1896 event. In 2016, 344 wrestlers from 54 countries will compete in 18 events.
Here's a look at some of the aspects of the game: