There are several several balance types. Click on the cog wheel or the arrows to switch the balance types.
Future Balance - The balance including all future transactions entered. If you post date a transaction, it is grayed out in the transaction register, but Future Balance will include it in its Balance. You could also call this the Absolute Balance or Overall Balance.
Cleared Balance - The balance of the cleared transactions. Check the cleared checkbox of a transaction in the Transaction Register to change this balance.
Current Balance - This is the balance as of Today. This balance does not include future transactions.
Available Funds - The balance available for you to withdrawal from your bank account or spend on your credit card before you are overdrawn or exceed your credit limit. Available Balance is the difference between the Current Balance and the Limit entered in the Account Info for the current account.
Available Credit - The balance available for you to spend on your credit card or credit line account before you exceed your credit limit.