Roles
Your team members can be Players, Guests, or Non-Players.
Players
Players are always invited to all games and events. Most of your people will be players.
Guests
Guests (you might call them "backups") are only invited if you manually request them. To invite guests, hit the Invite Guests button on the activity page (below the list of guests). You can also invite them individually.
Teams use the Guest role to have a group of backup players they can call on when they are looking short. Other teams use the Guest role to invite try-out players to selected events e.g. training or a scrimmage.
Non-Players
Non-Players don't receive invites. This role is intended for long-term absentees (e.g. players who are injured) or for admin staff who also don't need to see invitations.
Non-players can see the team's schedule, so it is good for fans or ex-players who want to keep in touch.
Where the non-player is an alternate contact for a player, they will get an invite. This is typically for when they're a parent or guardian to a child on a youth team.