Anyone who is entered in the MySoccerLeague.com database and has an assigned role is considered a user. The first user in your league is the League Administrator, who is entered by MySoccerLeague.com. All other users in the league are then entered by other users. A user is entered when being assigned a role. A user that does not currently have a role is still in the database, and will show up in searches when being given a new role.
See Adding Users for procedures and rules for adding and editing users.