CloudFlare usually just serve you a cached version of the site to increase performances and reduce the bandwidth. It automatically caches CSS, images and scripts but the rules are customizable.

Seriously? Downvoted for stating a fact?

https://support.cloudflare.com/hc/en-us/articles/202775670-H...

No it does not. Resources, such as css, js, pictures, often yes.

You don't get cached hackernews page because they use cf in front. As the other commenter said, it's nonsense.