The 21st century introduction of ‘the cloud’ as the ubiquitous solution for all things computing was a bigger milestone for technology than most people realised at the time. The importance of the cloud to worldwide technology is only now beginning to come into focus thanks to a full range of technology services that are a direct offshoot of the cloud mentality. The services include infrastructure as a service (IaaS), software as a service (SaaS), and platform as a service (PaaS). Each of these services is independent in some way, yet intrinsically connected in others. Without them, could we still manage to operate in the technology environment? Absolutely. But we would not operate as powerfully, efficiently, or cost-effectively. Infrastructure as a Service If cloud computing were built as a pyramid on the three services of IaaS, SaaS and PaaS, IaaS would be the foundation. Cloud infrastructure is essentially built on IaaS, creating an environment of self-service models by which customers can assemble, maintain, and monitor their own data centre hardware remotely. IaaS includes, but is not limited to: Real or virtualised computing environments Data storage Networking and networking services. The main advantage of IaaS is access to all the hardware and tools necessary to create and run a data centre or collocation environment, without the need to invest in equipment ownership, physical building space, utilities, and so forth. IaaS customers also assume full responsibility for managing and maintaining the applications and data running their equipment. With that responsibility comes the kind of complete control that supports flexibility, scalability, and virtual data centre building. Examples of IaaS include Amazon EC2 and Microsoft Azure. IaaS services are utilised both to create virtual data centres from scratch and to temporarily extend infrastructure to handle increased workloads. Platform as a Service The second layer in the cloud computing pyramid is PaaS. PaaS services are primarily designed to support software development and deployment by providing customers a ready-made environment that includes network infrastructure, server hardware, operating systems, and server software. PaaS is built mainly on virtualisation technology that makes it possible to create isolated cloud environments for software development. Customers benefit from PaaS in a number of ways, including scalability. They can requisition resources on an as-needed basis, scaling up and down as demand dictates. All of this can be done without any substantial investment in hardware, software, or network resources. Developers are free to concentrate on application development and scalability. Examples of PaaS include Apprenda, Azure, and Heroku. Each of these services incorporates an operating system, programming language, and execution environment. Software as a Service At the top of the cloud computing pyramid is software as a service. It turns out that SaaS is the largest market for cloud computing services, and it is also one that continues to grow exponentially. It is a cloud computing model that delivers software to clients for their use, without the need for them to install or manage software locally. In the SaaS environment, all applications are delivered and managed by third-party vendors who take responsibility for everything within the software realm. Applications are typically executed in the cloud environment and delivered to end-users via web browsers or purpose-built GUIs. The need for any locally hosted software is eliminated. Just about any type of software can be run in the SaaS environment. Storage networking software, productivity applications, middleware, operating systems, and even virtualisation software can be delivered as a service and maintained by third-party service providers. Examples of SaaS include GoToMeeting, Salesforce, and the full range of Google apps, all offered as cost-effective collaborative tools that enhance productivity at the enterprise level. Making the Most of the Cloud Vendors and clients may dispute the superiority of some cloud services over others, but the one thing all the services have in common is this: they are facilitating networking and computing strategies that make the most of the cloud. Technology will continue pushing forward to eventually remake our current understanding of IaaS, SaaS, and PaaS. New services will also emerge over time, and those who keep up will follow technology into the future, while those that don't will fall behind.