SQL Server is a relational database management system (RDBMS) from Microsoft that's designed for the enterprise environment. As a database server, it is a software product with the primary function of storing and retrieving data as requested by other software applications which may run either on the same computer or on another computer across a network (including the Internet).
SQL Server runs on Transact -SQL(T-SQL ), a set of programming extensions from Sybase and Microsoft that add several features to standard SQL, including transaction control, exception and error handling, row processing, and declared variables.
It provides enhanced flexibility, scalability, reliability, and security to database applications, and make them easier to create and deploy, thus reducing the complexity and tedium involved in management of database.