Unit 2 - Concept of cloud computing

 CBSE Revision Notes

Class-11 Computer Science (New Syllabus)
Unit 2: Computer Systems and Organisation (CSO)

Concept of cloud computing

A cloud refers to a distinct IT environment that is designed for the purpose of remotely provisioning scalable and measured IT resources. The term originated as a metaphor for the Internet which is, in essence, a network of networks providing remote access to a set of decentralized IT resources. Prior to cloud computing becoming its own formalized IT industry segment, the symbol of a cloud was commonly used to represent the Internet in a variety of specifications and mainstream documentation of Web-based architectures. This same symbol is now used to specifically represent the boundary of a cloud environment. It is important to distinguish the term "cloud" and the cloud symbol from the Internet. As a specific environment used to remotely provision IT resources, a cloud has a finite boundary. There are many individual clouds that are accessible via the Internet. Whereas the Internet provides open access to many Web-based IT resources, a cloud is typically privately owned and offers access to IT resources that is metered. Much of the Internet is dedicated to the access of content-based IT resources published via the World Wide Web. IT resources provided by cloud environments, on the other hand, are dedicated to supplying back-end processing capabilities and user-based access to these capabilities. Another key distinction is that it is not necessary for clouds to be Web-based even if they are commonly based on Internet protocols and technologies. Protocols refer to standards and methods that allow computers to communicate with each other in a pre-defined and structured manner. A cloud can be based on the use of any protocols that allow for the remote access to its IT resources. To understand this in simpler terms let’s understand it like this most of us are using Google drive or onedrive or Icloud. When you store something on it it’s stored on their servers and not on your phone or PC. You can access it from anywhere you don’t need you laptop or phone to access this data you can simply login from any device and can access you data this is what we call cloud computing where we can access some one’s resources for our use. This thing is not limited to storing data only you can use all resources like RAM, CPU etc. just by paying some bucks.

Cloud can be privately owned by a company or it can be public

Private Cloud: Private cloud refers to a model of cloud computing where IT services are provisioned over Private IT infrastructure for the dedicated use of a single organization. A private cloud is usually managed via internal resources.
The terms private cloud and virtual private cloud (VPC) are often used interchangeably. Technically speaking, a VPC is a private cloud using a third-party cloud provider's infrastructure, while a private cloud is implemented over internal infrastructure. Private clouds may also be referred to as enterprise clouds.

Public cloud: A public cloud is one based on the standard cloud computing model, in which a service provider makes resources, such as virtual machines (VMs), applications or storage, available to the general public over the internet. Public cloud services may be free or offered on a pay-per-usage model. Public cloud is a fully virtualized environment. In addition, providers have a multi-tenant architecture that enables users -- or tenants -- to share computing resources. Each tenant's data in the public cloud, however, remains isolated from other tenants. Public cloud also relies on high-bandwidth network connectivity to rapidly transmit data. Public cloud storage is typically redundant, using multiple data centers and careful replication of file versions.

Parallel Computing:  Parallel computing is a type of computing architecture in which several processors execute or process an application or computation simultaneously. Parallel computing helps in performing large computations by dividing the workload between more than one processor, all of which work through the computation at the same time. Most supercomputers employ parallel computing principles to operate. Parallel computing is also known as parallel processing. Parallel processing is generally implemented in operational environments/scenarios that require massive computation or processing power. The primary objective of parallel computing is to increase the available computation power for faster application processing or task resolution. Typically, parallel computing infrastructure is housed within a single facility where many processors are installed in a server rack or separate servers are connected together. The application server sends a computation or processing request that is distributed in small chunks or components, which are concurrently executed on each processor/server. Parallel computation can be classified as bit-level, instructional level, data and task parallelism.