So as you can see here,

so we've seen before

the two different tables or two different relations that were before.

It's the student major from

electrical engineering department and

student majors from the computer science and engineering department.

So they were two different relations,

R and S. And the union of these two,

we put them all in the same relation,

and the output will be that way.

So assume that this was a table,

R and this one was the table,

S. So these were before the Union they were two different relations.

And then when we did R union S,

it resulted into this relation.

So generally speaking, when we talk about Relational Algebra,

the output of a Relational Algebra operator,

like the union for example, is another relation.

So you union two relations and the output is another relation,

mathematically speaking. Thank you.