Teams are formed based on player age and ability.  Younger players can play on older teams, but older players cannot play on younger teams.... this is called "playing up".  The intent is to challenge all players for their development.  IN HOUSE teams tend to be co-ed teams composed of boys and girls.  For the U8 and U10 age groups, the club will hold evaluations prior to a season start in an attempt to distribute the skill levels equally on each team.  This way, all teams will be able to compete and it encourages development of all players.  Travel teams are typically playing in State administered leagues where there are girls teams and boys teams that are broken into age groups.  Girls can play on boys teams, but boys cannot play on girls teams.  Any team with a boy, qualifies as a boys team.