Referred to the evidence project page http://www.evidenceproject.eu/
Software distribution model where a company provides the maintenance, support and operation that the client will use during the time he hired the service. The client will use the system hosted by that company, which will maintain the client's information in their systems and provide the necessary resources to exploit that information.
The capability provided to the consumer is to use the provider’s applications running on a cloud infrastructure.
PaaS model is a cloud services category that provides a platform and environment that allow developers to create applications and services that work through the internet. It allows users to create software applications using tools provided by the provider, choosing the functions they wish to include to solve their needs and discarding those they do not need.
The capability provided to the consumer is to deploy onto the cloud infrastructure consumer-created or acquired applications created using programming languages and tools supported by the provider.
Infrastructure as a Service usually works through a virtualization platform. Instead of acquiring servers, space in data center or network equipment, customers buy all these resources from an external service provider. A fundamental difference with virtual hosting is that the provisioning of these services is done completely through the web.
The capability provided to the consumer is to provision processing, storage, networks, and other fundamental computing resources where the consumer is able to deploy and run arbitrary software, which can include operating systems and applications.