Ionic sass - -s/--sass flag

Hey,

Ionic newbie here (somewhat a newbie - after a brief spell with it a few months ago). Can somebody please tell me what the benefit of providing the -s/--sass flag when running the following?

ionic start --sass <path>

I know very little about SASS, but as far as I can tell - if I exclude the flag, I still get a <project>/scss/ folder with a single file in this called ionic.app.scss.

Also <project>/www/lib/ionic/scss contains a bunch of *.scss files if I exclude it.

So what benefit/addition does including the flag -s/--sass provide in comparison?

Hope that is clear.