"Cloud computing is where software applications, data storage and processing capacity are accessed over the internet." (Three Ways to Cloud Compute) SaaS, PaaS, and IaaS all play a role in cloud computing.

• SaaS (Software as a Service): Allows users to access existing online applications and store associated data in the cloud.
• PaaS (Platform as a Service): Allows users to create cloud applications using tools, solutions and components provided in the cloud--an application hosting and deployment environment.
• IaaS (Infrastructure as a Service): Allows businesses and organizations to run applications on cloud hardware: virtual machines, servers, storage, load balancers, and networks.