The definition of cloud computing is the service of providing data, resources and software over a network as opposed to receiving them through individual software products downloaded onto the computer.
An example of cloud computing is an Internet-based data storage service.
Computing in which software and applications are stored on remote servers and accessed via the Internet by users from their PCs.
Hardware and software services from a provider on the Internet (the "cloud"). Cloud providers replace inhouse operations and are invaluable for companies, no matter their size or applications. Cloud servers can be configured to handle tiny or huge amounts of traffic and expand or contract as needed.Is Every Internet Function Cloud Computing?Not exactly. Many people believe that backing up their data or storing their photos over the Internet is cloud computing. However, this is really storage rather than computing (see cloud storage). In addition, thousands of applications access a server over the Internet behind the scenes for additional processing and updates. Although they obtain data from the cloud, that is not technically cloud computing either.Cloud computing really started with software as a service (SaaS), which offers applications online that were previously installed in the user's computer. Salesforce.com was notably one of the first. Secondly, tech giants such as Amazon, Google, Microsoft and IBM, with years of experience running their own datacenters, began to offer companies large and small an external alternative to inhouse operations. The combination of application services and general-purpose infrastructure is what cloud computing is all about. See Amazon Web Services, Google App Engine and Windows Azure.Cloud Computing Features(Self Service) The customer (end user or IT professional) signs up online, activates and uses the hardware and software from start to finish without having to phone the provider to set up the account. Depending on the service contract, tech support is available either online or by phone.(Scalability) Additional servers can be quickly configured to process more data or to handle a larger, temporary workload such as Web traffic over the holidays.(Speed) Major cloud providers are connected to the Internet via multiple Tier 1 backbones for fast response times and fault tolerance.SaaS (Software as a Service)Starting in the late 1990s, SaaS providers offered an entire application to the end user online, eliminating all internal hardware and software maintenance. Myriad applications running from a Web browser use this model, including email, Google's G Suite and Salesforce.com's CRM. Customers pay by the number of users. For IT, this has been a paradigm shift. Although there are no more maintenance problems, there are security and privacy issues when company data are stored in the cloud.IaaS (Infrastructure as a Service)Also called "cloud hosting" and "utility computing," IaaS provides the basic hardware, which is typically a server and virtual machine (VM) environment. IaaS customers deploy their applications as well as their own "stack" of system software (database, language runtime engine and other system components). See virtual machine and technology stack.PaaS (Platform as a Service)PaaS includes the stack so that customers need only deploy their applications. With IaaS and PaaS, customers pay by some combination of server size, execution time, amount of sharing, storage and downloads. There are several options. See runtime engine and system software.FaaS (Function as a Service)At the most granular level, FaaS is a newer paradigm. Customers pay only for the time it takes to execute specific tasks (see serverless computing).Datacenter Operation Is Major WorkInstead of operating its own servers, it can be more economical for a company to use the cloud and eliminate the security, maintenance, network and environmental issues with inhouse datacenters. In addition, commercial clouds may meet military standards for natural disasters.The Virtualization FoundationThe cloud employs server virtualization, which, among other benefits, allows application workloads to be easily added and removed as self-contained modules. In fact, virtualization has been a major enabler of the cloud computing model. However, the amount of work required by the customer differs greatly. Configuring virtual implementations on servers can range from being almost entirely automatic to requiring that the IT administrator be thoroughly familiar with very technical software. See server virtualization and virtual machine.Private and Hybrid CloudsEnterprises can create private clouds in their datacenters that employ the same cloud computing infrastructure used on the Internet. The private cloud provides the same flexibility and self-service capabilities, but with complete control of privacy.A hybrid cloud is both private and public. If the private cloud is overloaded, applications are activated on the Internet cloud. Extending software and databases from internal servers to a provider's servers and managing both venues from a central console are major issues in cloud computing administration. See fog computing, cloud management system, personal cloud, Windows Azure, thin client, cloud storage, colocation, Open Cloud Manifesto and Web application.