Difference between Getchar( ),Getch( ) ,Getche( )

What is difference between Getchar( ) , Getch ( ) , Getche ( ) ?

Getchar ( ) - It will accept a character from keyboard , displays immediately while typing and we need to press Enter key for proceeding.

Getch ( ) - It just accepts a keystroke and never displays it and proceeds further. Normally we use it at the end of the main ( ).

Getche ( ) - It will accept a character from keyboard , displays it immediately and does not wait for Enter key to be pressed for proceeding.