Character is a fictional represetation of a human figure. In order to create a fiction there must be an interaction of characters; these characters develop through their dialouges, actions, or reactions.
Character is central to fiction, and essential to it. Fiction is a story that happens to one or more character, and is (almost always) about the experiences, sufferings, and changes one or more character goes through.
The importance of character in a story is the importance of caring. A superficial, static or stereotypical character simply will not engage the attentive reader in a meaningful relationship. The characteristics ascribed need not be entirely or even substantially laudatory by conventional standards; what is essential is that they be recognizable as being of the human condition.