What is the difference between Saas, PaaS, and IaaS in the world of cloud computing?

SaaS (Software-as-a-Service) refers to applications that are delivered as a service over the Internet, without needing to install and run the applications at the customer's own site. A SaaS solution must be accessible via a web browser, be multitenant, have subscription-based pricing, and have automatic version upgrades, patching and security updates.

PaaS (Platform-as-a-Service) refers to the software infrastructure components needed to create and run applications over the internet. These software infrastructure components consist of operating systems, middleware, databases, and development tools delivered as a utility (similar to electricity or water) so that users only pay for what they use.

IaaS (Infrastructure-as-a-Service) consists of the physical server hardware, storage, and networking delivered as a service. Pricing is metered such that users only pay for what they use.