Nimbostratus cloud
Under Luke Howard's first systematized study of clouds, carried out in France in 1802, three general cloud "forms" were established based on appearance and characteristics of formation: "cirriform," "cumiliform" and "stratiform." These were further divided into upper and lower types depending on altitude. In addition to these three main types, Howard added two names to designate multiple cloud types joined together: "cumulostratus," a blending of cumulus clouds and stratus layers, and "nimbus," a complex blending of cirriform, cumuliform, and stratiform clouds with sufficient vertical development to produce significant precipitation.
HP Cloud
There can be different types of hybrid clouds for specific tasks. The Infrastructure as a Service (IaaS) model can be a hybrid cloud in that it could use operating systems and virtualization technologies from both a public and private cloud infrastructure to provide cloud services. Other models that mix on-premises cloud with public cloud technologies include Platform as a Service (PaaS), which includes infrastructure services combined with development tools and middleware; and Software as a Service (SaaS), which is used to develop packaged software.