Can you please guide me about the basic concept of Journal Voucher ( JV ) ???

From my experience of auditing i have learned that there are five type of vouchers that can be used for accounting purpose. 

1). CPV (cash payment voucher) for Cash payment related transaction (usually for revenue expenditures or payment made through patty cash)

2). CRV (Cash Receipt Voucher) any transaction regarding cash receipt from customer or third party will be posted in system through CRV.

3). BPV (Bank Payment Voucher) Any payment processed through bank account will be recorded into system using BPV.

4). BRV (Bank receipt Voucher) Any payment received into bank account will be recorded into system using BRV. 

5). JV (Journal Voucher) any adjustment entries in which Bank and Cash do not effect will be recorded into system using JV. (credit sale, credit purchase, month end or year end adjusting entries or accrued expenses and rectification of accounting errors  will be posted into system using JV).