What is difference between two data types string and String?

[jagdeep gupta]

Both of these used same function. So why these two have been provided?

Secondly Why there is Not a constructor like:
String abc=new String("Hello") ;

[Shafi hashmi]

Hi jagdeep. Every dotnet language has its own data type and dotNet framwork has its own. All languages data types are maped to the framework data type by CTS(common type system). Thus 'string' is langguge data type and 'String' is framwork's data type and so on.
They are of struct type not classes..

[C Sharper]

They are the same thing. "string" is a C# keyword/alias for .NET type "System.String" . It is up to the developer which they use. Some developers who work in team environments like to use the .NET type so that others who reference their code, but may be developing in a different language can still understand their code. This is the same as using "int" instead of "Int32", or "bool" instead of "Boolean".

Strings are classes, but have been optimized by MC to not have to be initialized because of their extensive use. It should also be noted that Strings act like value types in that they are immutable, though they are actually reference types. So, when you edit a String it actually creates another string. These characteristics are why Microsoft included the StringBuilder in .NET.