Unregistered users and accepting answers, commenting and upvoting

Question

To be honest, until recently I did not know about the ability of unregistered users to ask questions.

How do they accept answers?

If they are not registered logic says they can't accept answers, they can't comment in case of a missing detail in their question. Same goes for upvoting an answer they like.

Correct, or does the browser hold a cookie or something to identify the user later?

I am asking this because many of the new users are not familiar with SE style, so they tend to treat it as a normal forum and they always miss information which requires editing the question or answering comments.

Am I missing something here?

Answer 1

Unregistered users are identified by a cookie stored in their browser. If they lose that cookie, they can recover access via the email recorded on their account, provided that they entered a valid email address. If the cookie is lost and the email is inaccessible, the account is no longer accessible.

Unregistered users have only limited possibilities to interact with the site. They can make posts, they can earn reputation, they can make comments (subject to the 50 reputation point threshold except on their own posts and answers to their own questions, just like registered users). The biggest limitation for unregistered users is that they cannot vote (they can however accept answers).

Registration is encouraged (and it's easy to do — if you don't want to associate your Stack Exchange account with Google, Facebook, Yahoo or other OpenID provider, then you can create a Stack Exchange OpenID account by clicking the “click here to sign up” link on the login page). However, it is not compulsory.

See Why should I register my account? for more information.