NULL value comparison

Good Day,

I'm trying to figure out why a postgresql query doesn't return what I'd expect with a query like this where there are
NULLvalues: 

select * from users where is_enabled<>'Y';

I'm expecting it to return all records where is_enabled is 'N' or NULL.  Perhaps my expectations are misguided.  Any
thoughtswould be appreciated. 

Thanks!
Michael


Example:

CREATE TABLE users (
    "name" char(50) NOT NULL,
    "is_enabled" char
)

insert into users (name, is_enabled) values ('Michael', 'Y');
insert into users (name, is_enabled) values ('Jeremy', 'N');
insert into users (name, is_enabled) values ('Sherry', NULL);


select * from users where is_enabled<>'Y';
+----------------------------------------------------+------------+
| name                                               | is_enabled |
+----------------------------------------------------+------------+
| Jeremy                                             | N          |
+----------------------------------------------------+------------+
1 rows in set (0.03 sec)