Computer resources and software services are sold in packages called service plans. A service plan includes the resources and services needed to set up and maintain one or more internet services such as an email box, an online database, a website and other web services on a single customer account.
The service plan is a computer resource and service package as a commercial offer. When customers buy service plans, they reserve rights to use a certain amount of hosting resources and services at a certain rate over a certain period in the future, usually starting from the day of purchase. Purchasing the service plan is equivalent to subscribing to the services listed in the plan. This is why computer resources and services provisioned for customer accounts are called subscriptions.
A corresponding subscription denotes the same amount of resources and services that are listed in the service plan, but that have already been provisioned for end users and are managed by the end users.