Computing was formerly linked to physical spaces. Today, everything is in the cloud. In those days, computer or server rooms usually housed huge computing devices. With the advent of cloud computing, however, users can have access to momentous computing power without huge investment. Cloud computing is an internet-based computing which enables shared processing capacity, storage space, data, software, applications and other resources to computers and other devices on demand through the "clouds", which is a metaphor for the Internet. Cloud computing is similar to grid computing, which describes a situation where unused computing capacity in a network is harnessed to tackle problems too intensive for typical home or office computers.
How does it work?
The main idea of cloud computing is to deliver traditional high-performance computing power, usually available to military, research or academic institutions, with the ability to perform tens of trillions of computations per second. To produce this type of huge power, cloud computing relies on the networks of large groups of servers with specialised connections to spread data-processing load across them. This system epitomises a shared information technology infrastructure, which is made up of large pools of systems that are connected. Frequently, virtualisation techniques, that is the creation of a virtual version of a server, storage device, network resources, operating system etc are used to amplify the power of cloud computing. Corporate institutions, governments and organisations working in all spheres of life and even individuals are now users of cloud computing all over the world.
Types of Cloud computing
Based on a location, we can have four types, namely: Public, private, hybrid (private and public) and community cloud. Public clouds, as the name suggests, are shared resources located on the premises of a cloud computing company delinked from end users' location. They do not have any control over it and there is a high vulnerability to attacks.
Private clouds are networks solely used by one organisation. Though not shared by others, they can be located outside the premises of the said organisation. Private cloud provides the highest level of security and control.
Hybrid cloud combines both private and public cloud. In one scenario, public cloud can be used to provide services to end users while confidential data are kept secure on private cloud. Community cloud connotes an infrastructure sharing situation between units of an organisation. For example, the Government of Ghana could run a community cloud for its ministries, departments and agencies which can be managed by an apex organ of government such as the National Information Technology Authority (NITA).
In his book, Cloud Computing and SOA Convergence in Your Enterprise, David S. Linthicum describes a more granular classification on the basis of service provided, termed as follows: Storage-as-a-service, Database-as-a-service, Information-as-a-service, Process-as-a-service, Application-as-a-service, Platform-as-a-service, Integration-as-a-service, Security-as-a-service Management/Governance-as-a-service, Testing-as-a-service and Infrastructure-as-a-service. However, in industry parlance, three types hold sway based on the services they provide, namely; Infrastructure as a service (IaaS), Platform as a Service (PaaS) and Software as a service (SaaS).
Infrastructure as a service (IaaS) involves offering hardware-related services using the principles of cloud computing such as database, disk storage or virtual servers. Flexiscale, Amazon S3, Rackspace and Cloud Servers are some of the industry's leading vendors in this area.
On the other hand, Platform as a Service (PaaS) provides users with development platform on the cloud. Google Application Engine, Microsoft Azure, Salesforce.com are typical players in PaaS.
Lastly, Software as a service (SaaS) provides users with complete software services on the cloud usually on pay-per-use basis. This is a popular and well-established sector with Salesforce.com pioneering online Customer Relationship Management (CRM) offering. Your typical online email providers like Google's Gmail and Microsoft's Hotmail, and Microsoft's BPOS (Business Productivity Online Standard Suite) or Google docs are examples of SaaS.
A number of companies are offering cloud-computing services in Ghana, making it easy for local organisations to take advantage of these services. Unreliable Internet means some organisations do not rely on cloud computing since they cannot access services when the Internet is down.
There is no 100 per cent security guarantee on the Internet. A popular case is when iCloud, which is Apple's cloud computing and storage service with over 700 million users as of February 2016, suffered a security breach in 2014, where intimate photos of celebrities were stolen from their iCloud accounts, among others. (http://www.bbc.com/news/technology-29237469 ) Irrespective of this breach, Apple and other cloud computing services providers which are hosting a lot of sensitive content across the globe take security seriously and are constantly investing heavily to ensure the integrity of content stored on the clouds.
Cloud computing offers a lot of advantages, especially for organisations that are not able to invest in the ownership of super computing resources in-house.