Parameter is a variable name defined by you (function writer) to contain any value given by User for the function to run. The value given by User is called argument.
With return. Most of the time you’ll have to return, because IRL we’re running a function to get the value it returned to be used somewhere else, e.g.:
let x = thisFunction()
we are expecting x to have a value whatever returned from invoking the function.
If you’re running a loop (e.g. to find every vowel in a string), you want the return at the end of the function (most of the time, because once it hits return, the function will stop and not run any line after the return). But if you want the function to stop right away after a (if else) condition is met, “That’s it! I’m done!” (e.g. find the first vowel in a string), you want to return in each if else statement, and sometimes we have to do both (when a function has a loop with if else statement). You’ll get this later on.
Anyway, great! You got this.