Availability Float is a time difference between deposits made, and the funds are actually available in the account. It is time to process a physical cheque into your account.
For example, you have $20,000 already in your account and a cheque of another $10,000 dollar is deposited in your account but your account will show balance of $20,000 instead of $30,000 till your $10,000 dollar cheque is cleared this processing time is known as availability float.