Think about what actually happens in a business on any given day. Cash comes in, cash goes out, goods are sold, goods are bought, money moves between the cash box and the bank, and occasionally something needs an adjustment that doesn't fit any of those neat boxes. If you tried to remember all of this in your head, you'd lose track within a week. So the accountant's solution is simple: every transaction gets written down on a slip of paper that is designed specifically for that kind of transaction. That slip is a voucher.

The intuition is this — a voucher is not just a record, it is a classified record. Instead of one generic form for everything, you have different forms, each pre-printed with the columns and headings that make sense for that category. A payment voucher has a space for "paid to" and "towards"; a receipt voucher has "received from" and "on account of." Because the form itself tells you what kind of transaction it is, the bookkeeping becomes mechanical and errors become hard to hide.

Now the precise statement. A voucher is a documentary evidence in writing that supports a transaction, showing its nature, amount, parties involved, and the accounts affected. The types of vouchers are the standard categories into which these documents are divided, each corresponding to a particular class of transaction.

There are two broad ways to slice them. The first is by who prepares them and when — source vouchers (created when the transaction happens, like a cash memo you receive) versus accounting vouchers (prepared by the accountant to record it in the books). The second, and the one that matters for your syllabus, is by the nature of the transaction itself. That gives you the six you listed.

A few things worth pinning down, because first-time students trip on exactly these.

The receipt voucher and payment voucher are mirror images. One records inflow, the other outflow. Both involve actual cash or bank movement. The contra voucher is the odd one out among the money vouchers — it records money moving within the business, from cash to bank or bank to cash, so no outside party is involved and the total cash-plus-bank balance doesn't change. That's why it's called "contra," meaning opposite or offsetting.

The sales voucher and purchase voucher are for credit transactions in goods. If the sale is for immediate cash, you'd typically use a receipt voucher instead, because the defining feature is the cash inflow, not the sale. This distinction — credit sale versus cash sale — is where most beginners slip. …