 <p>A self join joins a table to itself. The <code>employee</code> table might be joined to itself in order to show the manager name and the employee name in the same row.</p> <p>An inner join joins any two tables and returns rows where the key exists in both tables. A self join can be an inner join (most joins are inner joins and most self joins are inner joins). An inner join can be a self join but most inner joins involve joining two different tables (generally a parent table and a child table).</p>