equality

is?

Compares two objects by identity.

=

Compares two objects by content.

!=

Shorthand for (not (= ...)).

(is? 2 2) -> true
(is? 'foo 'foo) -> true
(is? "foo" "foo") -> false
(is? '(1 2 3) '(1 2 3)) -> false
(is? () ()) -> true

(= 2 2) -> true
(= 'foo 'foo) -> true
(= "foo" "foo") -> true
(= '(1 2 3) '(1 2 3)) -> true
(= () ()) -> true

(!= 2 3) -> true
(!= 2 2) -> false