Explanation:

All business transactions are recorded in the books of account depending on the nature of transaction. There are certain books which are compulsorily maintained by the business. 

Below are the books which are mandatory to maintained to record all the transactions:

1) Cash Book- It records all the cash transactions.

2) Sales & Purchase book- It records all credit sales and credit purchases.

3) Journal- It records those transactions which are not recorded in specific books. Purchase of assets etc.

4) Ledger- All above set of entries are to be posted in ledger to find out the balance of each account.