What is the Cloud?
'Cloud' is a buzzword which gets thrown around so often that it has almost lost all meaning. In simplest terms, 'cloud' services refers to any service (storage or otherwise) which utilizes zero or very little local computing and storage resources in order to deliver services. There are a large variety of cloud services, both for business and consumers, and all such services utilize technology that has been available for a long time, but utilize it in a novel way, and use the term 'cloud' in order to refer to this clever new way of using the technology.
The 'cloud' refers to a physical computing infrastructure comprised of millions of computing units which have multiple levels of redundancies which are developed and operated by companies such as Amazon, Google, Microsoft, and Dropbox.
The Basic Idea Behind Cloud Computing
The term 'cloud computing' has only caught on in the past few years, and has existed for a little longer than that; however, the concept of using shared resources to lower cost and improve efficiency and optimize performance has been around for a lot longer.
Cloud Computing Service Models
Infrastructure as a Service (IaaS) is a cloud infrastructure service which provides scalable virtual computing resources over the Internet. IaaS provides hosting hardware (servers, storage, memory, etc) as well as software, and is generally targeted to businesses. Aside from scalability, redundancy, ease of access, and desktop virtualization, a major draw for IaaS services is the ability for the customer to pay on a per-use basis, potentially preventing unnecessary spending on infrastructure.
Platform as a Service (PaaS) is similar to IaaS; however, it differs in that in addition to the hardware infrastructure, PaaS also provides an operating system, the environment for programming languages to be executed (e.g., PHP, ASP), the ability to create and manage databases, and web server. Cloud platforms are generally used by developers to get their software solutions to the end user.
Software as a Service (SaaS) is the service of providing access to remote application software, and database resources for end users without the requirement of installing local software or purchasing outright licenses. SaaS offers consumers, as well as businesses, to reduce startup cost, by eliminating the need to invest in hardware and software.
Types of Clouds
Private Cloud is the term used to describe a cloud infrastructure which is designed, deployed and operated, for a single entity.
Public Cloud is a service which provides capabilities to the public and is accessible over public networks. Public cloud services often offer a free service level with expanded services available at a fee (generally at several different service-levels).
Hybrid Cloud, as the name suggests, is a cloud service which combines both private and public cloud characteristics and offers both areas for private and public access.