Cloud computing is an information technology paradigm that enables ubiquitous access to shared pools of configurable system resources.
It's called cloud computing because the information being accessed is found in "the cloud" and does not require a user to be in a specific place to gain access to it. This type of system allows employees to work remotely. Companies providing cloud services enable users to store files and applications on remote servers and then access all the data via the internet.
Different Types of Cloud Computing
Cloud computing is not a single piece of technology, like a microchip or a cell phone. Rather, it's a system, primarily comprised of three services: infrastructure as a service (IaaS), software as a service (SaaS)+ and platform as a service (PaaS). SaaS is expected to experience the fastest growth, followed by IaaS.
(1) Software as a Service (SaaS): SaaS involves the licensure of a software application to customers. Licenses are typically provided through a pay-as-you-go model or on-demand. This rapidly growing market could provide an excellent investment opportunity, with a Goldman Sachs report projecting that by 2018, 59% of the total cloud workloads will be SaaS.
(2) Infrastructure as a Service (IaaS): A cloud Service" infrastructure as a service" involves a method for delivering everything from operating systems to servers and storage through IP-based connectivity as part of an on-demand service. Clients can avoid the need to purchase software or servers, and instead procure these resources in an outsourced, on-demand service.
(3) Platform as a Service (PaaS): Of the three layers of cloud-based computing, it is also a cloud service. PaaS is considered the most complex. PaaS shares some similarities with SaaS, the primary difference being that instead of delivering software online, it is actually a platform for creating software that is delivered via the internet.
Characteristics of Cloud Environments
According to NIST, all true cloud environments have five key characteristics:
- On-demand self-service: This means that cloud customers can sign up for, pay for, and start using cloud resources very quickly on their own without help from a sales agent.
- Broad network access: Customers access cloud services via the Internet.
- Resource pooling: Many different customers all use the same servers, storage, or other computing resources.
- Rapid elasticity or expansion: Cloud customers can easily scale their use of resources up or down as their needs change.
- Measured service: Customers pay for the number of resources they use in a given period of time rather than paying for hardware or software upfront.