A character refers to an interactive online humanoid representation of a game persona.
Characters controlled by a player are most often referred to as a character, but sometimes as an "avatar" or "toon". Characters controlled by the game are usually referred to as Non-player characters or NPCs. Players are allowed 8 different characters per server.
When a player has determined their primary character, it is referred to as his or her main character, or simply main. Sometimes this is the first character the player created and played, but often it is not. A player's main is usually the one that has seen the most play time and investment of resources. In addition to their main, many players have one or more alternate characters, or just alts. An alt is a character to which a player devotes less time and effort to than their main character.