There are certain features that only registered attendees (= with an account) can use:
Book a spot and interact within workshops (ask questions, participate in polls, download files, etc.).
Rate sessions.
Networking.
Other features, such as asking questions and voting in polls during lectures, receiving newsfeed notifications, viewing custom menu items, creating personal agendas, and more, do not require a profile. Therefore, even anonymous attendees can use them.
