Do computers have an identification?

Hi, so I was just curious if computers could themselves be identified while browsing the internet. For example, could an experienced hacker gain access to a computers serial number while browsing online, or anything else that would allow that person to fallow the computer's identity?

Thanks

Well, yes and no.

"Experienced hacker" normally cannot get your cpuid or hdd serial number (unless using some 0-day exploits which is rare situation).

But combination of your browser user-agent, javascript version, OS version, accept-language headers, etc... is usually unique enough. Visit https://panopticlick.eff.org/ to test your browser's uniqueness.