Cloud computing is the delivery of everything from IT infrastructure to applications and business processes as a service over the internet rather than a product.
Instead of having to maintain in-house servers and install software, shared resources are delivered to computers in a similar way to a utility service. Cloud computing increases IT capacity and capability for the individual user or company without having to continually invest in new infrastructure or train staff on new systems. Essentially it moves expenditure from CAPEX to OPEX.
The name ‘cloud’ is a metaphor for the Internet – cloud being used as a visual depiction of computer network infrastructure in diagrams. The concept of cloud computing was first suggested by American computer scientist John McCarthy in 1961, when he said that computer time-sharing technology might lead to a future in which computing power and even specific applications could be sold through the utility business model (like water or electricity).
Just like a utility service, the end user doesn’t need to know the exact location of the system used to deliver services. The tools and applications are accessed as if they were on the user’s computer and the user can connect from anywhere. Cloud computing services operate on a subscription or pay-as-you-go basis.
Cloud computing offers various services:
Infrastructure as a Service (IaaS). Storage and compute resources that can be used by developers and IT companies to deliver business solutions.
Platform as a Service (PaaS). For developers to be able to build applications on top of the compute infrastructure. Developer tools are offered as a service to build further services, or data access and database services, or billing services.
Software as a Service (SaaS). Provides software so there’s no need to install it, manage it, or buy hardware for it. All that’s required to use it is a connection.
Amazon has played a key role in the development of cloud computing. It wanted to improve its internal computer network efficiency after realising, like many companies, that it was using as little as 10% of its capacity at any one time, just leaving room for occasional spikes. Having found that the new cloud architecture it implemented resulted in significant efficiency improvements, Amazon started providing cloud computing to external customers, and launched Amazon Web Service (AWS) on a utility computing basis in 2006.
Cloud computing has financial and operational benefits. Sharing resources across a large number of users lowers costs, and it ensures maximum use and efficiency of systems, instead of having individual or in-house systems that are under-utilised. Cloud computing is scalable, elastic and good for business continuity and disaster recovery.