Inner join

Inner joins can happen between two tables which are in different database as well as different servers but the servers should be linked.Inner joins give matching records records from both tables.You can use fully qualified name in joins like servername.database.dbo.tablename if the tables are in different servers and database.Example of an inner join

table AA has fields like rollno(1,2) , firstname (siddharth,rohit)
table BB has fields like rollno(2,3) , lastname(chauhan,batra)

then the join syntax would be:

select  a.firstname,b.lastname from AA a,BB b
where a.rollno=b.rollno

the result will be:  rohit    chauhan

rohit from first table and
chauhan from second table