Clustered Index in SQL Server

In this article I would like to talk about Indexes in SQL Server. Indexes are used to improve the performance of the queries. Database Index is similar to the one at the back of any book. You have one big book with 1000 pages and want to find information about Transactions then either you can read page by page till you find the information or just open the Index page and look for the information and use that information to find the full length content.