Race is a category that usually applies only to humanoids. Each adventurer has a race that his or her player selects at character creation. Members of a race have various characteristics in common. A character’s race confers certain traits to the character and helps determine the character’s starting languages.
The races that players choose from are often referred to as character races, and the adventurer members of a race typically have racial traits that other members of the race lack.
Published in Rules Compendium, page(s) 61.