Difference between Ledger balance and Available balance? Help!?

Yesterday, i only had $1 in my checkings account (i'm a college student =X), and my other deposited a check into my bank for $1,300. Today I checked my account recorders, and it says that I have $1108 in my "available" balance, and $1,300 in my "Ledger" balance. Qhy isn't there $1,300 i my available account? What does this mean?