About Making Library
What is the purpose of this line: Morse(int pin);
  


It is the method that is called when you create an object of class Morse when only passing a single int:

Morse somemorse(1);



  
  If any, what is the name of this line?
  


It has multiple names, depending on what aspect you care about:


It is a constructor for the class Morse.
It is a forward declaration for the method Morse::Morse(int).