Infrastructure as a Service (IaaS): is a method of providing computing, storage, networking, and other functionality over the Internet. IaaS allows businesses to use web-based operating systems, applications, and storage without having to purchase, manage, and support the underlying cloud infrastructure. The most popular examples of IaaS platforms include Amazon Web Services (AWS) and Microsoft Azure.Examples: Go GridSay no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essay Features: Instead of purchasing hardware outright, users pay for IaaS on demand. The infrastructure scales based on your compute and storage needs. Saves costs for businesses to purchase and maintain their own hardware. Because data is in the cloud, there can be no single point of failure. Allows virtualization of administrative tasks, freeing up time for other work. Platform as a Service (PaaS) : Developers have traditionally leveraged on-site infrastructure components (servers, storage, networking) to design and deploy applications. PaaS recreates this infrastructure in the cloud, allowing developers to design simple and highly complex applications on a pay-as-you-go basis. PaaS providers also offer resources such as development tools, libraries, and database management systems, so developers using PaaS don't have to worry about infrastructure logistics at all. Example: Google App Engine Features: PaaS provides a platform with tools to test, develop and host applications in the same environment. It allows organizations to focus on development without having to worry about the underlying infrastructure. Vendors handle security, operating systems, server software and backup. Facilitates collaborative work even if teams work remotely. Software as a Service (SaaS): Refers to applications provided over the Internet on a subscription basis, as opposed to paid, downloadable software on the front end. SaaS apps run on a provider's remote servers, which is why SaaS is also known as "web-based software" or "on-demand software". Access SaaS apps through your browser. SaaS is popular among businesses and has become the most common delivery method for business apps in areas such as accounting, enterprise resource planning, and virtualization. Examples: Microsoft Office, Google apps Features: SaaS providers deliver software and applications to users via a subscription model. Users do not have to manage, install or update software; SaaS providers handle all of this. Data is safe in the cloud; equipment failure does not result in data loss. Resource usage can be scaled based on service needs. Applications are accessible from almost any device connected to the Internet, from virtually anywhere in the world. Three basic cloud deployment patterns comprise a natural provisioning hierarchy, allowing you to explore opportunities for applying the patterns together. The next sections briefly highlight considerations for two common combinations. a) IaaS + PaaSA The PaaS environment will be built on an underlying infrastructure comparable to the physical and virtual servers and other IT resources provided in an IaaS environment. A cloud provider would normally not need to provide an IaaS environment from its own cloud to make a PaaS environment available to cloud consumers.b) IaaS + PaaS + SaaSAll three cloud deployment models can be combined to establish levels of IT resources building on each other. For example, the environment already:.