A Character is a name that is used as a label for all "living" parts of a game. When using the word "character", the term applies to all people controlled by humans and all A.I. in the game. The name is ambiguous to "Player" and is used on this wiki as a standard of naming for all "Players", "Actors", "People", and "A.I.".
A sentence that normally would read:
"Interestingly, Master Chief can jump into these taps..."
With the replacement of "Character" in the place of "Master Chief" it would read:
"Interestingly, characters can jump into these taps..."
Eliminating the name "Master Chief" eliminates any discussion of how the sentence should be worded. For instance, one may argue that it should be "the Master Chief" or "a Master Chief". Using the word "Character" makes a simple and universal standard for naming the player.