The cComparison Of SQL Server 2014

Microsoft has released three major versions of SQL Server since SQL Server 2008, incrementally adding and enhancing data management capabilities in response to industry trends and customer demand.
Alongside these SQL Server releases, Microsoft has released new generations of the Windows Server operating system, expanded the Windows Azure cloud platform, and evolved Microsoft Office into a premier tool for business analytics and data management.
In this picture you can see what different between SQL Server version.