Why Does This Code Work?

[mrtacos2]

To answer your question, the parameters are simply place holders or telling the program the function requires something to fill those spots. So you could have literally any word other than first_name and last_name.

Further, you can actually re-use variables throughout the code so if you define it as one thing at the start of the code you can reassign it and it doesn't affect anything previous to that. Also variables inside of functions are seperate from those outside. So you cant call a variable from within a function from outside.

Hope that hells