INNER JOIN --only shows matching rows from both tables
2. LEFT ( same as LEFT OUTER) -- shows matching rows from both tables + all rows from LEFT table
RIGHT (same as RIGHT OUTER) -- shows matching rows from both tables + all rows from RIGHT table
3. EQUI JOIN - NOT Explicitely supported by SQL SERVER
but the meaning is an inner join using EQUALITY as JOIN condition
4. FULL OUTER - all matching rows in both tables + all unmatching rows from both tables.
5. SELF JOIN - both implicit and explicite syntaxes are supported.
SQL Server doesn't support Natural join and Using clause syntax
Look at this article also :
How to join SQL Server tables where columns include NULL values}