Microsoft SQL Server Programming FAQ Index ( good collection of topics on SQL Server).
http://www.tek-tips.com/faq.cfm?pid=183

JOIN Types the following is a summary of http://www.tek-tips.com/faqs.cfm?fid=4785

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- INNER JOIN
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Ex.
SELECT Team.Name, Matches.id
FROM Team INNER JOIN
Matches ON Team.id = Matches.HomeTeam

Note:
Returns all rows in which a column on the left table matches one on the right.

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- OUTER JOIN
**********************************************************

1. LEFT OUTER JOIN:
   Ex.
   SELECT Team.Name, Matches.id
   FROM Team LEFT OUTER JOIN
   Matches ON Team.id = Matches.HomeTeam

Note:
Similar to the INNER JOIN except that for all records in which a column does not exist for the left hand side table a NULL is returned

2. RIGHT OUTER JOIN
   Ex.
   SELECT Team.Name, Matches.id
   FROM Team RIGHT OUTER JOIN
   Matches ON Team.id = Matches.HomeTeam

Note:
RIGHT OUTER JOIN - This JOIN is just like the LEFT OUTER JOIN except the Right_Table is the table that will have every one of its records in the result set and if no record is found in the
Left_Table then its columns in the result set will be NULL

3. FULL OUTER JOIN
   Ex.
   SELECT Team.Name, Matches.id
   FROM Team FULL OUTER JOIN
   Matches ON Team.id = Matches.HomeTeam

Note:
FULL OUTER JOIN - This JOIN is a combination of both. All records from both Left_Table and Right_Table are in the result set and matched when they can be on the Join_Condition when no record is found in the opposit table NULL values are used for the columns.
So a query of

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- CROSS JOIN
**********************************************************
Ex.

Note: