How its works Wayback Machine?

Hello, I don't know if this is the right area for this.

I was looking for the history of a domain on the Wayback Machine and the question came to me: How do they save website captures?

I'm a programmer and I have some ideas, for example, do they download the site (similar to HTTrack Website Copier) and store it (which may involve more and more storage space) or do they just go to the site and retrieve the html? But in this second case, as it saves only the pure html (without the css/js), when changing these imported files it would not break the html?

Any more ideas? I'm a dev, but I've never thought deeply about how this works.

They probably do something more like the former with some sort of scraper. Based on the Archive It site and some information on Archive itself and the Wayback machine, they may use some sort of combination of user submitted sites to index, partnerships with larger tech companies for important sites to store and possibly just whatever they feel like.

If they did the latter, how would they be able to go to a point in time?

AMD sponsors the storage space. That's all I knows about this website.