Difference between String and string in c#

There is not a big difference between String and string in C#.

String is an object in the System class. So whenever you declare the using System namespace in your class. You can use the String object.

string is a language specific type in .Net Framework itself.(CLS -> Common Languge Specification).

For ex:
--------

using System;

namespace Test
{
public class Test
{
public void TestMethod()
{
String s1 = "Change Is The Only Constant In The World.";
Console.WriteLine(s1);
Console.WriteLine(Environment.NewLine);
string s2 = "Think big acheive big.";
Console.WriteLine(s2);
}
public static void Main()
{
Test t = new Test();
t.TestMethod();
}
}
}

Output:
-------
Change Is The Only Constant In The World.
Think big acheive big.