When you want to publish your database changes across different instances of SQL Server e.g. One on your local machine, Three instances on Azure (Development, Staging, Production), 5 instances on other data centers across the globe, What will you do ? With a single change e.g. adding a simple column, change to stored procedure, adding new tables, and then keeping versions of each change in separate .sql files, makes it difficult to manage.
So by using SQL Server Project template in Visual Studio 2013 you can make your life easier. In this video I have practically explained how you can work with SQL Server Project templates.