Need Help UnderStanding the Code

who([H|T], B) :-
	member(H, B), !,
	who(T, B).
	who([_|_], _).

I want to understand this code I am new to learn Prolog

Do you know about gtrace/0 ?

See: The Graphical Debugger

No actually Iam not familiar with gtrace/0

See: https://stackoverflow.com/a/53337075/1243762

I tried the using trace but actually not getting what these predicates are actually doing for what task they were wriiten

Then you need to get a book and work through it.