Joins means combining. In SQL Server JOIN clause is used to combine rows from two or more tables, based on a related column between them. Please note that only JOIN clause behave like INNER JOIN in the most of RDBMS databases.

Example of Join

Lets we have ORDERS table somethings like:

Notice that the CUSTOMERS column in the ORDERS table refers to the "CustomerID" in the "Customers" table. The relationship between the two tables above is the "CustomerID" column. Then, we can create the following SQL statement (that contains an INNER JOIN), that selects records that have matching values in both tables:

                                SELECT Orders.OrderID, Customers.CustomerName, Orders.OrderDate
                                FROM Orders
                                INNER JOIN Customers ON Orders.CustomerID=Customers.CustomerID;
                                

and it will produce something like this:

Types of Join

Here are the different types of the JOINs in SQL Server