Payment methods define the way you prefer for customers to pay you, and how you like to pay your vendors. The method can vary for each customer or vendor. Examples of typical payment methods are bank, cash, check, or account.
You can assign a payment method to customers and vendors so that the same method is always used on the sales and purchase documents you create for them. If needed, you can change the method on the sales or purchase document. For example, if you want to pay a particular purchase invoice in cash rather than by check. This does not change the default payment method assigned to the vendor.