Answer by Pradeep Kumar Mishra for What is the difference between String and string in C#?

Both are same. But from coding guidelines perspective it's better to use string instead of String. This is what generally developers use. e.g. instead of using Int32 we use int as int is alias to Int32

FYI“The keyword string is simply an alias for the predefined class System.String.” - C# Language Specification 4.2.3http://msdn2.microsoft.com/En-US/library/aa691153.aspx