Cloud Computing is the delivery of computing as a service rather than a product, whereby shared resources, software, and information are provided to computers and other devices as utility over a network. The end-user can access the resources from everywhere (computer, cellphone, tablet, etc) because the service runs from the cloud, not in the end user physical computer.
Cloud Computing location
The cloud computing has 4 locations:
- Public cloud is open and is where pretty much all the services that run over internet are located. Some examples are service providers like Microsoft or Google.
- Private cloud for enterprise. The data center architecture is owned, managed and operated by a single company a used for a private group of users. Federal agencies and departments opt for private clouds.
- Community cloud for an especific community group. The infrastructure is shared by several organizations and supports a specific community that has shared concerns. It is used for mission, security requirements, policy, etc.
- Hybrid combination of two clouds that remain unique entities but are bound together by standardized or proprietary technology. Companies can maintain control of an internally managed private cloud while relying on the public cloud as need. NASA Nebula is an example where private cloud is used for research and development, and public cloud to share datasets with external partners and the public.
Models of Cloud Computing
There are three models of type of services offered:
- Infrastructure as a Service (IaaS): It offers compute power, storage and networking infrastructure as a service via the public Internet. Organizations rent computing power and disk space, so they access them from desktop PCs through a private network across the Internet. The most successful IaaS providers are Amazon Web Services, GoGrid and rackspace.
- Platform as a Service (PaaS): It evolves providing a platform on which a customer can run his own applications. The three biggest PaaS providers today are Google, Microsoft and Salesforce.
- Software as a Service (SaaS): It is the most common model of cloud service because the application exists in the cloud and can be consumed from any browser. So, the cloud users do not manage the cloud infrastructure and platform on which the application is running. Microsoft Online Services and Google apps are the most used.
Nowadays most of the users use cloud computing. In the next table you can see a rundown of the share of Internet users who have done a select set of online activities that involve storing data online or accessing applications in cyberspace.