Infrastructure as a service (IaaS) – provides users with access to raw computing resources such processing power, data storage capacity and networking.
Platform as a service (PaaS) – provides computing, storage infrastructure and a development platform layer with components such as web servers, database management systems and software developments kits.
Software as a service (SaaS) – offers application-level services tailored to a wide variety of business needs, such as customer relationship management, marketing automation and business analytics.