functions.php vs. @import

I’ve successfully created child themes using the @import url, but recently I came across a child theme helper I was using which says and I quote, so I don’t mess it up,

“A functions.php file that is used to link your child theme to your master theme (this replaces the older version that was linking via the @import code in style.css which is now not the recommended way.”

This php is pretty much gibberish to me, though at the end it does refer to ‘/style.css’

I guess my questions are, 1, is this the preferred way to do this and 2, is there somewhere I can go to understand the various “enqueue” commands in this file. Or three what exactly does this file do?

Thanks, ernie