Postings in General Ledger Accounting 
Manual postings from Financial Accounting and postings made using Business Application Programming Interfaces (BAPIs) can be posted specific to accounting principles.
In a ledger approach, you post with a ledger group, and to the accounting principles assigned to the ledgers that the ledger group contains. The values are updated in the respective CO versions for which the accounts are defined as cost element.
To determine the relevant accounting principles, ledger group assignments are taken into account in which ledgers from the ledger groups used in the posting are marked as representative ledgers.
In an accounts approach, if there are items with cost elements, the CO versions that represent the accounting principles to which the posted accounts are assigned, are updated.
Prerequisites
You have configured the settings for the versions and the currency and valuation profile.
If you use an accounts approach, you have assigned accounting principles to the G/L accounts.
For more information, see Parallel Accounting with Accounts (Accounts Approach) in Customizing for Parallel Accounting.
If you use a ledger approach, you have assigned ledgers to the accounting principles.