What is join? Mention its types.

Join depicts the relationship between two or more tables. It combines row of different tables and enables you to select data with reference to data of some other table. There are several joins in database like CROSS JOINs, NATURAL JOINs, EQUI-JOIN, etc. Two most important joins are –

• INNER JOIN – this join returns values that have matching record in both the tables. In this, blank rows are combined in middle.
• OUTER JOIN– it returns all the records of left table. It also returns the values that match with the right table. Blank rows are put in specified side by joining tables in other side.