Journal voucher is the voucher in which all the adjustment related entries and non cash non bank transactions are come ijournal eg-dep, some of them book the bills in journal and
whereas they make a payment they record in payment eg-contractor bill
Contra appears two times in two sides of a account an account will be care for as contra when
1, Cash deposited in bank
2, cash with drawn from bank for office use
3, cheques deposited in bank
4, transfers from one account to another account