string keyword
Use the string keyword to declare a string variable. The string keyword is an alias for the System.String class.
For example.
string name; name = "Tom Hanks";
Another example.
string [] array={ "Hello", "From", "Tutorials", "Point" };
char keyword
The char keyword is used to set array of characters.
For example.
char[] ch = new char[2]; ch[0] = 'A'; // Character literal ch[1] = 'B'; // Character literal
Another example.
char []letters= { 'H', 'e', 'l', 'l','o' };