What does the dollar sign mean?

I am just learning CSS and html and have been watching videos about using the grid. The grid is not difficult to understand except for all the $'s all over everything. I have tried looking online and not gotten anywhere.


Can you give an example of some code you are looking at? When I see a $ it means jQuery to me.

Here is one of the videos about CSS. If you look at the CSS ‘coding’ it is full of $'s. As in background color: $black; to name just one example.

Thank you.
I believe this is SCSS, something like:

I need to review this myself because I completely forgot about it.

Thank you. Sass is mentioned in the video and I’m sure this is the answer to my question.