What is the difference between On-account Receipt and Unapplied Receipt?

Unapplied payment:

The status of a payment for which you can identify the customer, but you have not applied or placed onaccount all or part of the payment. For example, you receive a check for $1200.00 and you apply it to an open debit item for$1000.00. The remaining $200.00 is unapplied until you either apply the payment to a debit item or place the amount On Account.

Account payment:

The status of a payment of which you apply all or part of its amount to a customer without reference to a specific debit item.

Examples of these are prepayments and deposits.