Question
What is the difference between a subscription and a domain in Plesk?
Answer
Subscriptions are a combination of resources available and permissions granted to a user. They allow to isolate different customers in the shared hosting environment by creating different system users for each subscription and can hold multiple domains, subdomains, domain aliases and custom settings within itself.
Domains, on the contrary, exist only within a subscription and can only be used to link domain names to Plesk objects: they can hold mail accounts, serve static or dynamic content or any other services.