print_full_name_to_console.js

// Remember, this is a comment because it is after two slashes.
// The web browser ignores comments - they are just for the humans.

function print_full_name(first_name, last_name) // Here we declare the function name and arguments
{ // <-- This starts the function
  console.log("Here is a full name:"); // This line is run first when the function is called
  // And then this line is run,
  // which pieces together the first_name argument, a space, and the last_name argument to create a full name:
  console.log(first_name + " " + last_name); // Which gets printed to the console.
} // <-- And then this tells the browser that the function is finished.

// Keep in mind that JavaScript doesn't really care about whitespace (spaces, tabs, and new lines)
// so you could put all this (EXCLUDING COMMENTS) on one line and it wouldn't change anything.