A more thorough explanation:

A voucher is a document that confirms the payment or discharge of a debt. It can also be a written or printed authorization to disburse money.

For example, when you pay your rent, your landlord may give you a receipt as a voucher to confirm that you have paid the rent. Another example is when a company gives its employees vouchers to use for business expenses, such as travel or meals.

In the past, a voucher was also a person who called on another person as a witness to support a warranty of title. It was also the tenant in a writ of right.

Overall, a voucher is a useful document that provides proof of payment or authorization to spend money.