With the SiteVIN forum / blog registered users are those who own an account in SiteVIN. You can open an account using the standard signup (which will create a full web site for you) as well as the quick signup (will create a personal page which you could grow into a full web site later).
As a registered user you can sign in to any SiteVIN forum / blog with your SiteVIN login name and password and enjoy a number of benefits:
Your postings will contain a link to your SiteVIN website or personal page.
If you have uploaded a photo in the Personal Info section of your SiteVIN account, it will be displayed in forum postings.
You can have the ability to edit your own postings if this option has been allowed by the forum / blog owner.
You can skip the login next time by checking the "Remember Me on This Computer" option.
You can be assigned a moderator of a forum / blog on another SiteVIN website.
Anonymous users on the other hand do not own SiteVIN accounts and can identify on a forum / blog with their name and email address.
The forum / blog owner can give different rights to registered and anonymous users with regard to posting messages or comments - for instance, allow only registered users to start a thread, but let both anonymous and registered users leave comments.