available v current posted balance?

Hi, this is my first bank account and I had a check on hold since it was a large amount I'm guessing, and it's not longer pending but it shows an available of $3 (what I had before the check) and $1000+ in the current posted balance, and under deposits not available for withdrawal is the check amount. What exactly does that mean? That I can use the money just not withdrawal it or?
I was on hold when I called and then it hung up so I'm trying to get some insight before trying to call again. Thanks!