The Different Layers of Cloud Computing are IaaS, PaaS, and SaaS.
IaaS: Infrastructure as a Service
IaaS, or Infrastructure as a Service, refers to the hardware, network equipment, and web hosting servers that web hosting companies rent out to consumers. The IaaS layer of Cloud computing is comprised of all the hardware needed to make Cloud computing possible.
PaaS: Platform as a Service
PaaS, or Platform as a Service, refers to the middle layer of the Cloud used for development by web developers, programmers, and coders. The PaaS layer of the Cloud is used to create applications, programs, software, and web tools.
SaaS: Software as a Service
SaaS, or Software as a Service, is the topmost layer of the Cloud. SaaS serves as the layer of the Cloud which the vast majority of consumers use. Built on top of both IaaS and PaaS, Software as a Service provides applications, programs, software, and web tools to the public for free or for a price.