A Ledger is the actual account head to which you identify a transaction and must be used in all Accounting Vouchers. Without a ledger we cannot record any transactions.
Ex: Purchase, payments, sales, Receipts, etc, all these accounts heads are ledger Accounts.
All Ledgers have to be classified into Groups. Classification of Ledgers to the appropriate groups is very important. These Groups and Ledgers are classified to Profit & Loss or Balance Sheet. The creation and usage of Groups in Tally.ERP 9 has been explained earlier. Now you will learn how Tally.ERP 9 works with Ledgers.
More :
Pre-defined Ledgers in Tally.ERP 9
Creating a Ledger with Advanced Usage
Displaying / Altering a Ledger Account