Character constants

Characters are single letters or digits such as '1', 'H' or '?'

Constants store a value that is set once and then never changes.

Character constants let you give a character value a name so you can use it to make your code easier to read or to set options for your code that the user wont be able to change.

In this example, a constant called KEY_QUIT is set to the character value of 'Q'