A purchase journal is an accounting journal and it is also a prime entry book/daybook/main entry book which is used in an accounting system to keep track of the orders of items placed using accounts payable.[1]
Simply a purchase journal can be defined as the main entry book which is used to record credit transactions (credit purchases) for resalable purposes.[2]
The Source document which is used as an evidence in recording transactions into purchase journal is Purchase invoice/invoice received/original invoice
Credit purchase of current assets/Non current assets are not considered when recording in Purchase journal.