Introduced: Wrestling was one of the original nine sports included in the first modern Olympics programme in 1896. The women's competition was added in 2004.
Greco-Roman wrestling was the first style of wrestling included in the Games, with freestyle added in 1904.
Events: Freestyle and Greco-Roman disciplines are divided by weight class. Men compete in six Greco-Roman events and six freestyle. Women only compete in freestyle with six events.
Technique and style: Wrestlers in the Greco-Roman discipline may only engage their arms and upper bodies, while freestyle competitors are permitted to use their arms and legs, attacking their opponent above and below the waist.
There are two main ways to win an Olympic wrestling match: Pinning an opponent's shoulders to the mat, which immediately ends the match, or securing points through moves like holds.
Different actions secure different point levels, ranging from one to five.
Rules and scoring: Olympic wrestling matches contain two three-minute periods.
Referees must protect the safety of the wrestlers but also ensure the bout maintains proper momentum without "faults" or violations inside the nine-metre mat.
Top competitors: Look for the hosts to shine, Japan's women having claimed 11 gold medals across the four most recent Games.
Sources: International Olympic Committee, Tokyo Organising Committee of the Olympic and Paralympic Games, United World Wrestling