Mappings is a fancy way of saying, "let's take what your data field is called, and match (map) it to a certain header name".
Attribute mappings is used to map person or transaction attributes to dynamic fields that are used in the application.
Attribute mappings already contain predefined mappings as example, but you can change them according to your needs by clicking on Edit button.
AMOUNT field should be mapped to the amount attribute you want to use for transaction summary calculations.
CREDIT field is used to identify transaction direction (incoming, outgoing) and needs to be mapped to an attribute that is responsible for it. And it should have a value specified in boolean true field that means outgoing transaction.
FROM_ACCOUNT, TO_ACCOUNT, FROM_NAME and TO_NAME are fields that are used in transaction summary to display sender and receiver accounts and names accordingly.
DATE_COMPLETED used to show the transaction date in the transaction summary.
FIRST_NAME, LAST_NAME, COMPANY_NAME used to display a person's full name in alerts and other places.
STATUS is used to display statistics only about transactions with certain status in the transaction summary. E.g. only about completed transactions. So, it needs to be mapped to an attribute that is responsible for the transaction status. And it should have a value specified in boolean true field that means e.g. completed transaction. Please note that the value is case sensitive. So, if the status value is sent as 'COMPLETED' then it should be added to the mappings accordingly as well. If you leave it empty, all transactions, regardless of their status, will be used in the summary.