What are the two basic kinds of electronic signals?

I'm guessing that what you're really asking is: 

             "What are the two fundamental ways to add
              information to an electronic signal ?"

Information is added to an electronic signal in either analog form
or digital form.

For a couple of decades now, we've gotten so good that we can do
both at the same time, making an electronic signal carry MORE
information that way.

Did you ever figue this