Substantive Procedures- Bank

-Agree the reconciliation’s balance per the cash book to the year?end cash book. q- is there any difference between cash book and year end cash book?? i dont get it? -Trace all the outstanding lodgements to the pre year?end cash book, post year? end bank statement and also to the paying?in book pre year end. q-what is the understanding behind this procedure?? and whats paying-in book pre year? -Trace all unpresented cheques through to a pre year?end cash book and post year?end bank statement. q- why pre year end cash book and post year end bank statement? i am not able to understand these procedures?