What is the difference between JOIN and UNION?

Question

What is the difference between `JOIN` and `UNION`? Can I have an example?

Answer 1

UNION makes two queries look like one. JOIN is for examining two or more tables in a single query statement

Answer 2

Join involves joining two or more tables together upon a common relationship between the tables regardless if the column length of those tables in the query expression are not the same. For example:

select name, address, state from b

join c on b.id = c.id

For union, the tables columns we are joining together must be of same length

select name from b

union

select name from c