Given two sets of data: * Inner Join -- having items specified by the ON in common are returned only * Outer Join - all items are returned with matched as one record * LEFT join, -- all items on the left and matching items on the right * RIGHT join -- all items on the right and matching items on the left. There are also quasi join -- * INTERSECT - Like a inner join but all columns are used * UNION - like an outer join but all columns are used * Except - like a left or right join but only items not found in second set are returned. using all columns