G.I. Joe is the code-name for an elite military counter-terrorist unit. In other words, the entire TEAM's name is "G.I. Joe." There is no one individual character named "G.I. Joe." (Unless, of course, you get into the story of Joe Colton, which came later and tied it all back into the original G.I. Joe guy, but that gets complicated, so we're ignoring it for now).
As far as distinguishing this G.I. Joe team from other forms of G.I. Joe, the catch-phrase "A Real American Hero" is often used, or even just ARAH. This is the 3.75" action figures that achieved incredible popularity in the 1980s, disappeared in 1994, and returned in 2000 to a lesser extent (so far).
Anyway, the Joe team is made up of specialists in many different areas. Each has been through grueling Special Forces training to be the best there is in the nation. Each is identified only by a code-name.
For example, this big guy is Roadblock. He's the heavy machine gunner of the team, and usually carries around a truly gigantic machine gun.
This is Hawk, the leader of the team. He's a Brigadier General.
This is Duke, the First Sergeant, and therefore, effectively, the Field Commander of the team.
Chuckles is the undercover specialist of the Joe team.
And Snake-Eyes just rocks. He's the resident ninja/commando of the team.
Flint is another of the officers.
