What do we mean by "Real Websites"? If you select betaPRESS or or deltaPRESS you can host multiple domains. These are NOT your traditional Addon domains. Addon domains are a problem because they share the resources of the main domain. They are also a security risk as their file systems are not isolated from the main domain and other addon domains. When we say "Real Website" we mean that each of your domains gets the full 3gb and 3 CPU cores and do not share this resource limit. Each domain is set up on Plesk's subscription level meaning it has its own file system and is completely isolated and secure.