How space is compared in where condition I've come across below query where it is column being compared the space character.

SELECT  *
FROM    company
WHERE   emp_name &gt; ' ' -- space char  
AND     emp_id = 123
AND     active_flag = 'Y';


emp_name is VARCHAR2

Here WHERE emp_name &gt; ' ', does it consider ASCII value of the space while comparing? Could someone please explain this.
I have Oracle on local. But you can see example on SQLFiddle

create table a1 ( i varchar(10));

insert into a1 values('a');
insert into a1 values(' ');
insert into a1 values('v ');

select * from a1 where i &lt;&gt; ' '; 
select * from a1 where i = ' ';
select * from a1 where i like '% %';