Bank reconciliation means some of the transaction entered in the cash book not in the pass book and some transaction entered in the pass book not in the cash book. In other words we can say that always opposite entry in cash book and pass book. The bank pass book indicates the amount paid into the bank and the amount withdrawn there form. The pass book balance or any given data must be the same as the balance shown by the bank column of the cash book on the same date.The reason responsible for the difference may be delay in intimation, time gap between recordings of transaction in cash book and pass book due to errors and omissions in cash book and pass book.