1. On-Demand Self-Service: Users can provision computing resources, such as server time and network storage, as needed automatically without requiring human interaction with each service provider.
2. Broad Network Access: Cloud services are available over the network and can be accessed through standard mechanisms that promote use by heterogeneous thin or thick client platforms (e.g., mobile phones, laptops, and workstations).
3. Resource Pooling: The provider's computing resources are pooled to serve multiple consumers using a multi-tenant model, with different physical and virtual resources dynamically assigned and reassigned according to consumer demand.
4. Measured Service: Cloud systems automatically control and optimize resource use by leveraging a metering capability at some level of abstraction appropriate to the type of service (e.g., storage, processing, bandwidth). Resource usage can be monitored, controlled, and reported, providing transparency for both the provider and consumer of the utilized service.