Boxing is a fighting style that appears in the Street Fighter games.
Boxing is considered one of the oldest sports in the world; while its modern incarnation and rules are predominately European, boxing is considered a global sport.
The participants wear gloves; any moves other than punches (i.e. kicks, elbows, knees, headbutts etc), as well as punching the opponent below waist height, are against the rules. Some grappling is common, but is usually broken up by a referee. It has four basic types of punches: straights, crosses, hooks, and uppercuts.
Boxing has many styles and stances. In the Street Fighter series, Balrog, who is based on Mike Tyson, uses his signature Peek-a-Boo style. This emphasizes keeping the gloves in front of the face, as well as "bobbing and weaving" the body to both dodge attacks and gain momentum for powerful blows. Balrog, however, does not follow the rules, and uses headbutts, stomping, tripping, and bites, paying homage to Mike Tyson's infamy as a rule-breaker and poor sportsman.
Dudley uses the Southpaw style of boxing with the left side acting as the lead; he focuses on skill and technique for quick hits and distanced defense. His left arm is his dominant hand, and is kept back to ensure a wide swing for stronger attacks.
Ed utilizes a boxing style infused with Psycho Power; referred to as "Psycho Boxing". He also uses illegal moves like kicking, but generally fights cleaner than Balrog (by not using hook punches). The way Ed fights (excluding the Psycho Power-related attacks) may (questionably) be based on MMA-styled kick-boxing.