Infrastructure-as-a-Service (IaaS) delivers fundamental computing techniques, network, and storage resources to consumers on-demand, over the Internet, and on the process of pay-as-you-go basis. Using cloud infrastructure on every pay-per-use scheme enables companies to save on the costs of acquiring, managing, and maintaining their own IT infrastructure. Plus, the cloud is easily accessible to all. Most major cloud service providers — including Amazon Web Services (AWS), Google Cloud, Microsoft Azure, IBM Cloud, and — offer IaaS with their all cloud computing services. 

Platform-as-a-Service (PaaS) provides customers with a complete cloud platform — hardware, software, and infrastructure — for developing, running, and managing all applications without the cost, inflexibility, and complexity of building and maintaining that platform on-premises. Organizations may turn to PaaS for the same reasons they look to IaaS; they want to increase the speed of development on a ready-to-use platform and deploy applications with a predictable and cost-effective pricing model.

Software-as-a-Service (SaaS) provides While Software-as-a-Service (SaaS) is similar to the IaaS and PaaS uses described above, it actually deserves its own mention for the indisputable change this model has brought about in the way companies use the software. SaaS offers all the software access online via a subscription, rather than IT teams having to buy and install it on different individual systems.