JOIN means "to combine two or more tables".
A JOIN clause is used to combine rows from two or more tables, based on a related column between them
We've a table named Students and Teachers in our database that contains the following records:
Notice that the "ROLL_NO" column in the "Teachers" table refers to the "ROLL_NO" in the "Students" table. The relationship between the two tables above is the "ROLL_NO" column.
We can make different type of Join statement with this kind of relations in a table.