Bill of Exchange

Dear professionals
Please explain followings:

-The drawee is a person (usually bank) on whom a bill is drawn and who has not accepted it.
-The drawer is the person (or persons) making the payment ( the buyer)
-The payee is the person ( persons) in whose favour the drawer has directed the payment ( the seller)

According to the above text which is taken BPP Text book ( page 95) drawee is bank, drawer is buyer and payee is seller. Definition of these terms also the same in Opentuition’s F4 Notes.
Do you think that it is correct?

In order to understand Bill of Exchange I watched videos and found that Seller is Drawer, Buyer is Drawee and usally Bank is payee.

Please I need your help to understand Bill of Exchange correctly. Thanks in advance.