Cloud computing

Cloud computing delivers computer-based services (software, hardware/servers, databases, storage) over the Internet, accessible from anywhere on any smart device. Cloud service providers usually charge on a pay-per-use basis, like electricity.

• We already use the cloud when we back up photos and files online or host a website.
• A user can run big applications or process large data without owning the storage or processing power, as long as they are online.
• It gives cost-effective, on-demand resources: no huge upfront investment for a new organisation.

Three service models (everything 'as a service'):

• Infrastructure as a Service (IaaS): computing infrastructure such as servers, virtual machines (VMs), storage and backup, network components and operating systems. The user configures, deploys and runs any software on remote hardware and pays per use, saving the cost of buying, setting up, maintaining and securing it.
• Platform as a Service (PaaS): a ready platform to develop, test and deliver applications without managing the underlying setup. For example, to run a web application built with MySQL and Python, you can rent a pre-configured Apache server with both already installed. The user fully controls the deployed application.
• Software as a Service (SaaS): on-demand access to application software, usually by licence or subscription, with no installation: Google Docs, Microsoft Office 365, Dropbox.

In India: the government's cloud initiative is 'GI Cloud', named 'MeghRaj'.

Example (new): a student editing a group project in an online word processor from a cyber café uses SaaS; a start-up that rents a ready coding environment with its database and language preinstalled, so it only uploads its own app, uses PaaS.