Function Parameters

Question

What exactly are function parameters? How do they work?
I know there's more to parameters than just this:
function Test(a, b) {
alert(a + b);
)
Test("Hello ", "World!");
Take this code I wrote for example:
https://code.sololearn.com/WsEXgBv9x9Xx/?ref=app
I have no idea what a and b are in the second function.
The point is, I know very little about parameters and they have me confused when I see them in complex Javascript.

Answer 1

sort function uses compare function to make comparison in the sort algorithm. 2 compare input parameters are needed, must be a and b. if return a-b will generate ascending order sorted array, else if return b-a will generate descending order sorted array.

Answer 2

Function :
Function are used to reduce code in your program.
For example :
Suppose your program is based on adding numbers.
Instead of doing addition every time , you can define function once and call it as many times as you want.
Examples :
function add(a,b)
{
console.log(a+b);
}
add(1,2) //ans 3
add(5,9) //ans 14
and so on...
Hope this helps you.

Answer 3

But what exactly is a and b in the sort function?
Parameters are so confusing to me xD