To create a new identifier column when creating a table
This value will be assigned to the first row in the table. If you leave this cell blank, the value 1 will be assigned by default.
This value is the increment that will be added to the Identity Seed for each subsequent row. If you leave this cell blank, the value 1 will be assigned by default.
For example, suppose you want to automatically generate a 5-digit Order ID for each row added to the orders table, beginning with 1000 and incremented by a value of 10. To do this, you would check the Identity property box, type an Identity Seed of 1000, and type an Identity Increment of 10.
Creating and Modifying Identifier Columns