What’s the difference between SaaS, PaaS, and IaaS?

Technology has evolved rapidly in recent decades. Dipping computer and server hardware prices led to the introduction and adoption of modern cloud computing. Models such as software as a service (SaaS), platform as a service (PaaS), and infrastructure as a service (IaaS) have emerged largely as a result of the desire to harness the computing power of a grid (a network of servers).