Overview of Amazon Web Services AWS Whitepaper
Cloud Computing Models
Types of Cloud Computing
Cloud computing provides developers and IT departments with the ability to focus on what matters most
and avoid undifferentiated work such as procurement, maintenance, and capacity planning. As cloud
computing has grown in popularity, several different models and deployment strategies have emerged to
help meet specific needs of different users. Each type of cloud service and deployment method provides
you with different levels of control, flexibility, and management. Understanding the differences between
Infrastructure as a Service, Platform as a Service, and Software as a Service, as well as what deployment
strategies you can use, can help you decide what set of services is right for your needs.
Cloud Computing Models
Infrastructure as a Service (IaaS)
Infrastructure as a Service (IaaS) contains the basic building blocks for cloud IT and typically provide
access to networking features, computers (virtual or on dedicated hardware), and data storage space.
IaaS provides you with the highest level of flexibility and management control over your IT resources and
is most similar to existing IT resources that many IT departments and developers are familiar with today.
Platform as a Service (PaaS)
Platform as a Service (PaaS) removes the need for your organization to manage the underlying
infrastructure (usually hardware and operating systems) and allows you to focus on the deployment
and management of your applications. This helps you be more efficient as you don’t need to worry
about resource procurement, capacity planning, software maintenance, patching, or any of the other
undifferentiated heavy lifting involved in running your application.
Software as a Service (SaaS)
Software as a Service (SaaS) provides you with a completed product that is run and managed by the
service provider. In most cases, people referring to Software as a Service are referring to end-user
applications. With a SaaS offering you do not have to think about how the service is maintained or how
the underlying infrastructure is managed; you only need to think about how you will use that particular
piece of software. A common example of a SaaS application is web-based email which you can use to
send and receive email without having to manage feature additions to the email product or maintain the
servers and operating systems that the email program is running on.
Cloud Computing Deployment Models
Cloud
A cloud-based application is fully deployed in the cloud and all parts of the application run in the cloud.
Applications in the cloud have either been created in the cloud or have been migrated from an existing
infrastructure to take advantage of the benefits of cloud computing. Cloud-based applications can be
built on low-level infrastructure pieces or can use higher level services that provide abstraction from the
management, architecting, and scaling requirements of core infrastructure.
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