Q.A bank statement is a copy of :

A firm's Cash Book and the bank's Pass Book record the same bank account from two different points of view, and a transaction is often recorded by one side before the other catches up — cheques issued but not presented, cheques deposited but not yet collected, bank charges, direct bank collections/payments, and dishonoured cheques are the most common causes, alongside occasional errors on either side. A Bank Reconciliation Statement is prepared periodically to identify and list every such difference, proving the two otherwise-mismatched balances are, in fact, consistent once timing differences and errors are accounted for — it is also a valuable internal-control check …