Can someone explain to me what this question is asking of me exactly without giving me exactly the answer? I want to learn.

```
Let A={kirk,spock,mccoy} and B={spock,scotty,sulu}. What is A Union B?
Let A={Kirk,Spock,Mccoy} and B={Spock,Scotty,Sulu} what is A intersect B
Let A={Kirk,Spock,mccoy} and B={Spock,Scotty,Sulu}. What is A except B
```

# Best How To :

What is A UNION B?

```
The result considering A and B have the same number of columns,
both of the result will be merged into on a single result set.
```

What is A INTERSECT B?

```
The result will be what both A and B have, can be similar to
INNER JOIN and other similar solution/work around.
```

What is A Except B?

```
The result will be all the values of A that B does not have, can
be similar to LEFT JOIN combined with filtering.
```

Good example: *Example .pdf link*

Credits to the owner of the .pdf