Semi-join in SQL Server

This is very interesting and good to know that Correlated sub queries is called as Semi-join in SQL Server.

Semi-Join returns rows from a table that would join with another table without performing a complete join.

Ex:

SELECT a.FirstName, a.LastName

FROM Person.Person AS a

WHERE EXISTS

(SELECT *

    FROM HumanResources.Employee AS b

    WHERE a.BusinessEntityID = b.BusinessEntityID

    AND a.LastName = 'Pritam');

GO