Cloud computing is the delivery of computing and storage space as a service to a distributed community of end users. It’s a common term for delivering hosted services over internet.
- Cloud computing is a model for delivering information technology services, whose assets are retrieved from the internet through web-based applications and tools.
- Cloud computing is so named because of the information being accessed is found in clusters that are available worldwide, by which not requiring the user to be in a specific place to gain access to it.
- The data that are accessible are provided by data centres worldwide, which are collectively called as clouds.
- Cloud computing is computing model, not a technology.
- The schema/model of cloud computing is, all the servers, networks, applications and other elements related to data centres are made available to end users.
- Cloud computing is computing model that is equivalent with Grid computing, Distributed computing.
- At the base, cloud computing is broader idea of converged infrastructure and shared services.
Cloud computing providers offer services based on three basic service models.
- Infrastructure as a Service (IaaS)
- Platform as a Service (PaaS)
- Software as a Service (SaaS)
Infrastructure as a Service (IaaS)
IaaS refers not to a machine that does all the work, but simply to a service given to businesses that offers users the power of extra storage space in servers and data centres. IaaS clouds offers.
- Virtual Machines
- File storage
- Load Balancers
- IP addresses
Platform as a Service (PaaS)
It is a category of cloud computing services model that provides a computing platform and a solution stack as a service. Application developers can put up and run their software solutions on a cloud platform without the cost and complexity of buying and managing the original hardware and software layers.
- Operating System
- Execution Runtime
- Web server
- Dev Tools
Software as a Service (SaaS)
SaaS has become a common delivery model for many business applications, as well as Accounting, Collaboration, Customer Relationship Management (CRM), Management Information Systems. Cloud providers set up and operate application software in the cloud and cloud users access the software from cloud clients.
- Virtual Desktop
The service models of the cloud computing has well-known features which are the reason behind the popularity of this computing model. The features are,
- Consumption based billing -Pay per use scheme.
- Rapid elasticity -Consumers can flexibly increase or decrease the capacity.
- Self service based model -Users have ability to upload, build, deploy, schedule, manage and report on their own.
- Location & device independence -Access on the go and from any device.
- Multi-tenancy -No additional resources like electricity, infrastructure, etc for servers.
- Reliability -Back-up facility using more than one server for an instance.
- Ease of maintenance -Since the applications don’t need to be deployed on client’s computer,
- Reduce financial overheads -Opting for cloud reduces financial expenses of a concern greatly.
- Less prone to failure -The cloud rarely goes down which makes it less prone to failure.
- Safety -Privacy, security and data integrity is guaranteed.
maintenance becomes centralized and easy.
Real Time Examples
There are loads and loads of real time examples of the cloud computing model that’s being used by millions of users in their day-to-day life.
Infrastructure as a Service - Amazon EC2, Google Compute Engine, HP Cloud.
Platform as a Service - Google App Engine, Heroku, Cloud Foundry.
Software as a Service - Google Apps, Office 365, GT Nexus.