UNION = OR?

Question: Are UNION and OR doing to same or different?

Comments: We check with some data.

Scripts:

create table test_tab ( num1 number, num2 number );
insert into test_tab values(10,15);
insert into test_tab values(20,23);
insert into test_tab values(17,20);
commit;
select * from test_tab;
NUM1 NUM2
---------- ----------
10 15
20 23
17 20
Result of OR:
select * from test_tab where num1 = 10 or num2 = 20;

NUM1 NUM2
---------- ----------
10 15
17 20
Result of UNION:
select * from test_tab where num1 = 10
union
select * from test_tab where num2 = 20;
NUM1 NUM2
---------- ----------
10 15
17 20
Conclusion:
Wow! The result of Union and OR clause is same.
So
UNION=OR
Do not come to conclusion with above result. Check with some other scenario.
Question: UNION and OR will give same result ?

Comments: check with some other data.

Scripts:

drop table test_tab;create table test_tab
(
num1 number,
num2 number
);
insert into test_tab values ( 1,1);
insert into test_tab values ( 1,1);
Result of OR:

select * from test_tab where num1 = 1 or num2 = 1;
NUM1 NUM2
---------- ----------
1 1
1 1
Result of UNION:

select * from test_tab where num1 = 1
union
select * from test_tab where num2 = 1;
NUM1 NUM2
---------- ----------
1 1
Result of UNION ALL:
select * from test_tab where num1 = 1
union all
select * from test_tab where num2 = 1;

NUM1 NUM2
---------- ----------
1 1
1 1
1 1
1 1
Conclusion:
Yes! The result of Union and OR clause is not same.

So
UNION<>OR