There are nearly 100 Samba Schools in Rio. They all compete during the Carnival but only a few ones parade in the Sambadrome.
Schools are ranked hierarchically into 6 levels or groups: SPECIAL, A, B, C, D and E. Each group contains between 8 and 15 Schools which compete among themselves to be the group-champion of the year. There is also the JUNIOR Schools group, which is currently composed by 18 Schools.
The top groups to parade in the Sambadrome are the SPECIAL one plus A and B groups.
Every year the champion Schools of each group are promoted to the immediately superior groups and the Schools to score the least points are downgraded to the immediately inferior group.
Therefore all Schools strive to improve their positions within the general contest and to become group champions. The champion of the Carnival is the champion of the SPECIAL GROUP.
It may take years for a School to reach the top groups since all Samba Schools begin in the lower ranks. School members are passionately committed to their Schools. They take it as a serious responsibility to make their School sparkle in the parades and rise in rank.
It is a life philosophy.