The default registration form for new users ask about name and email adress. If you want or need to collect additional information it is super easy. Perhaps you need to know your users phone number, nationality or if they are an employee or not. Svava allow you to design the registration form to meet your needs.
Note that users who have previously registered will be asked to fill the new fields next time they log in, so you will be able to collect this information from current users as well.