Pending transactions are purchases made through your credit, debit or gift card that have not fully cleared with the bank.  Pending transactions are not yet posted to your account, but instead they place a hold on the amount pending against funds in your bank, your gift card or your credit limit.  This is to ensure you have the availible funds to complete the transaction and to prevent the consumer from exceeding limits placed on their cards.

The downside to pending transactions is that if your transaction fails due to inputing incorrect information, it will still record a pending transaction to your account.  You will not be charged for the transaction, but you will not have access to the funds until the transactions are cleared by your bank.  Transactions can take anywhere from 3 - 14 days to clear depending on your card or bank.