How many extranet users can login to a sitecore website at the same time? Is there any limitation for the number of concurrent logins? NB: This question is not about sitecore users(Number of concurrent Sitecore Users), its all about extranet users.
Not for Extranet users.
If a Sitecore license restricts the number of concurrent users, that restriction applies only to CMS users, not to visitors to or extranet users on the published sites.