On-demand service in the context of information technology is a model of service delivery in which the customer can use the services at any time, wherever he needs them.
A perfect example of such a service is cloud resources, which can be provided by a service provider at any time via the Internet or a specially organized dedicated network connection.
On-demand cloud resources enable the end user to get any computing power, any storage capacity, and access to software instantly and almost unlimitedly for their needs wherever there is an Internet connection.
As a rule, on-demand services make it possible to get the required computing resources to the customer rather quickly without concluding long-term contracts and agreements. Often a simple online registration is enough to access such services. The second important advantage is flexible scalability; the customer uses the amount of resources he needs.