There are four basic member types: Team Owner, Manager, Player, and Non-Player. If you have a Club & League account, you will have two additional member types: League Owner and Commissioner.
League Owners control League and Club accounts. Typically this is the person responsible for billing for the club/league subscription. The league owner is a commissioner by default, with all the permissions that a commissioner has, and the only roster member able to grant or revoke commissioner status to other members. The league owner is also the default team owner for any teams in the club or league who have not yet been assigned an owner. There can be only one league owner per club or league account.
Commissioners can be either league-level commissioners with league-wide administrative access or division-level commissioners with administrative access limited to a specific division within the league. League-level commissioners can assign players to teams, create and edit registration forms, and manage general settings for the entire club or league, can manage league-wide Locations, and are able to send emails to everyone in the league. Division-level commissioners can assign players to teams within their division, send emails to teams within their division, and manage division locations that teams within their division can use when scheduling games and events. There can be as many commissioners as needed or desired within a league account.
Owners are assigned as the owner of a team/group. For independent teams, the owner is responsible for the team plan billing and is the only member able to grant or revoke manager status to other members (for Club & League teams, league owners and commissioners also have this ability). The owner is a manager by default, with all the permissions that a manager has. There can be only one owner assigned per team.
Managers can do things that players can’t, like create/edit games in the schedule, invite new players to join, update payments, etc. If there’s something editable within your team, the manager can do it (whereas a Player cannot). There can be as many managers as needed or wanted on a team (e.g. a coach, assistant coach, etc).
Players are what most of the roster members are by default. They can modify their own information like contact info, availability, etc, but not others' information. They cannot do things that a manager can, like create/edit games or invite new players.
Non-Players are roster members that don’t play in games. For example, someone who coaches but doesn’t play, an assistant coach, team mom, or even a team mascot. Functionally, there is no difference between a player and a non-player. Non-Players are listed separately from players on the roster, and they are not included in the player count on the Availability screen. Typically you will designate someone like a coach or team mom as both a non-player and a manager.
Family Members are people who have been added to a member's roster profile and sent shared access invitations. Those are shared access users who are sharing access to the team through the roster member’s profile and permissions.
Finally, there is a check mark indicator on the roster for TeamSnap Members, to indicate who has accepted their invitation to join the team. For more info on this, check out the article on the invitation process.