Purchase:

		Purchases are transactions that indicate that you bought services from a vendor.
		Purchases that are printed on documents you give to your vendors are called purchase orders.
		Unprinted purchases called miscellaneous purchases.

   Sales:

		Sales are transactions that indicate that items or services were sold to a customer.
		Sales that are printed on documents you give to your customers are called invoices.
		Unprinted sales are called as miscellaneous sales.

		Item invoice
		service invoice
		professional invoice or time billing invoice