Debit? Credit?- are accounting terminologies and most often than not, only accounting people understand these terms. Every transaction of a Company that has financial impact are recorded through a journal entry. Each journal entry composes of at least one debit and one credit; and the balance should always the same e.g. debit = 100, credit = 100. In SAP (FICO), financial transactions are recorded through a journal entry.

Posting key has 3 roles:

1. It determines the account type to be entered; whether it’s a customer account, vendor account, asset account or general ledger account.
2. It determines the type of posting; whether the account is a debit or credit.
3. Partly, it determines the entry screen layout of the line item.

Example: Posting key ’01′.

1. Account type allowed is only customer account. If the account entered is other than customer account, an error appears and transaction can not be posted.
2. The line item is a debit (positive or negative sign for an amount is not necessary to be entered).
3. Fields that will be displayed depends on the configuration of the posting key(and the field status group of the general ledger account).

Field Status Group (FSG), also determines partly the entry screen layout of the line item.
Entry screen layout means either fields are:
a. Display only – no information can be entered for display only fields.
b. Required – information should be entered e.g. select through dropdown or entered manully. Transactions can not be posted in the system, unless required fields are filled up.
c. Optional – you can input information or just leave these blank.