IaaS vs PaaS vs SaaS: What’s The Difference - XB Software

Infrastructure as a Service includes computing resources, such as virtual servers, storages and networks. It may be said that it can be imagined as virtual computers where operating systems, software, applications can be installed on. 

Platform as a Service is primarily designed for companies developing their own software. Companies using PaaS need to manage only applications and data with no necessity to manage the infrastructure.

Using Software as a Service, customers pay for the license and needed functionality, where a provider owns and maintains all the infrastructure.

Please read the article IaaS vs PaaS vs SaaS: Three Options — One Solution or How to Choose Between the Alternatives for more details about cloud computing services.