Are design systems that contain code the actual repositories for the code?

I'm currently doing some research on design systems so we can, hopefully someday, build our own.

While there are many examples out there, built on a wide range of platforms, the ones with code gave me some confusion.

We want to have a DS that not only guides our designers when building something that needs to conform to our standards, but we also want to have a place in which our devs can actually find the code for those components, so they can just copy + paste it; at least for the more common ones like filters and tables.

While I'm not a developer, I noticed that a lot of the design systems that contain code (usually tagged as 'react' or 'vue.js') show a code that starts with a "import this" and "import that".

Here's a good example from "Carbon Design System"

Does that mean that the solutions built with code that was copied from that page are actually importing information from the design system (which means that they will depend on it to work)?

If that is not the case, then I would have a follow-up question: is that code all, or nearly all, that would be necessary for a developer to actually implement it in a page; or are they just snippets that serve only a "live demo" purpose?

I would also appreciate links to design systems that manage to have this "just copy and paste the code and you're good" approach, if that is even a thing.

Thanks to all!