Just as Boxing is a much different animal than most other sports, the Boxing referee has a much different role than in other sports. The Boxing referee's job is not to simply enforce the rules but to protect the fighters from injury.
Like any other referee, the Boxing referee has some basic rules to enforce. The ref makes sure that the blows that are thrown are legal. You can't hit below the belt, on the back, on the back of the head, etc. In many fights (especially Heavyweight) the ref will spend a great deal of time breaking clinches. The ref also has to watch out for ridiculous things like ear nibbling. The ref is responsible for declaring whether a cut has been caused by a punch or accidental head butt. When a fighter falls down they rule whether it's a slip or an official knockdown.
The way in which a Boxing referee enforces the rules is different than in other sports too. While penalties abound in many sports they occur much less often in Boxing. Most of the time the Ref simply tells the fighter to stop doing whatever illegal activity he's involved in. "Stop holding!", "No more punching after the bell!", "Keep the punches up!", "None of that!", "Don't hold his head", etc. It's only when a boxer continues to break a rule that the ref uses one of his tools, the point deduction. This often occurs because of low blows. The only other tool for the ref is to actually disqualify a fighter.
Many referee's will start a fight by telling the fighters to "protect yourselves at all times." It then becomes the referee's most important duty to make sure that the fighters follow this rule. If a fighter becomes hurt to the point that they cannot stop their opponent from hitting them the referee will stop the fight. The referee will constantly assess the fighters abilities to protect themselves. Even if a boxer gets up before a ten count the ref will often stop a fight if he feels the man is in danger. When injuries (like cuts over the eye) impair a boxer's ability to defend themselves the ref will stop the fight. Or if the boxer sustains an injury that would become dangerous the ref will call the fight.
Because the Boxing referee's most important role is to keep the Boxers safe the ref has a much different relationship with the fighter than a ref in other sports. You only need to watch a few bouts to see the way they are very often father figures. They don't enforce rules during the match so much as chide the fighters for doing the wrong thing. When a boxer is in danger they will step between the fighters and usually hold onto the defeated fighter. They will hug them and pat them on the back almost as if to say, "It's ok, it's over, you fought well."
The "third man in the ring" in many ways actually makes
Boxing a sport. Without him it is merely a "fight" that would be illegal. When the boxers enter the ring they almost leave their "civilized" (and very often peaceful) selves behind. When the ref enteres the ring he keeps these things with him. The referee becomes the "lifeline" between the civilized and "barbarian" worlds that boxers travel between. | 
