I was browsing online, the definition of a bartender according to Wikipedia (just for kicks) and here is what it said:
Totally copied from Wikipedia
A bartender (barman, barkeeper, barmaid, mixologist, tapster among other names) serves beverages behind a bar in a bar, pub, tavern, or similar establishment. This usually includes alcoholic beverages of some kind, such as beer (both draft and bottled), wine, and/or cocktails, as well as soft drinks or other non-alcoholic beverages. He/She "tends the bar". A bartender may own the bar they tend or be simply an employee. Barkeeper carries a stronger connotation of being the purveyor i.e. ownership.  In addition to their core beverage-serving responsibility, bartenders also:
* take payment from customers (and sometimes the waiters or waitresses);
* maintain the liquor, garnishes, glassware, and other supplies or inventory for the bar (though some establishments have barbacks who help with these duties);
In establishments where cocktails are served, bartenders are expected to be able to properly mix hundreds to thousands of different drinks.
Bartenders also usually serve as the public image of the bar they tend, contributing to as well as reflecting the atmosphere of the bar. In some establishments focused strictly on the food, this can mean the bartender is all but invisible. On the other extreme, some establishments make the bartender part of the entertainment, expected perhaps to engage in flair bartending or other forms of entertainment such as those exemplified in the films Cocktail and Coyote Ugly. Some bars might be known for bartenders who serve the drinks and otherwise leave a patron alone while others want their bartenders to be good listeners and offer counseling (or a "shoulder to cry on") as required. Good bartenders help provide a steady clientele by remembering the favored drinks of regulars, having recommendations on hand for local nightlife beyond the bar, or other unofficial duties. They are sometimes called upon for answers to a wide variety of questions on topics such as sports trivia, directions, or the marital status of other patrons.
In regions where tipping is the norm, bartenders depend on tips for most of their income. Bartenders are also usually responsible for confirming that customers are of the legal drinking age before serving them alcohol.
I think my favorite part of the definition is the "unofficial duties". I actually had a guy ask me the marital status of one of our servers last week. I gave him the safe answer: "I don't know."