Public Cloud

Updated: Tue, 31 Mar 2015 by Rad

Public Cloud - A public cloud is based on the standard cloud computing model, in which a service provider makes resources, such as applications and storage, available to the general public over the Internet. Public cloud services may be free or offered on a pay-per-usage model.

Cloud-computing" by Mylife191 - Own work. Licensed under CC BY-SA 4.0 via Wikimedia Commons

While the public cloud is big business and attracts the world's largest providers, like Amazon Web Services and IBM, access to the public cloud itself is often inexpensive or free to establish and users are often, but not always, smaller scale enterprises or individuals.

The public cloud is sometimes regarded as less secure than private clouds.

Reasoning behind cloud

Private clouds tend to use older technology than public clouds
Public clouds shift capital expenses to operational expenses - it's pay as you go
Public clouds have better utilization rates
Public clouds keep infrastructure costs low for new projects
Public clouds offer greater elasticity
Public clouds get enterprises out of the "datacenter business"
Public clouds have greater economies of scale
Public clouds are hardened through continual hacking attempts

History of public cloud

The idea of an "intergalactic computer network" was introduced in the sixties by J.C.R. Licklider, who was responsible for enabling the development of ARPANET (Advanced Research Projects Agency Network) in 1969.

One of the first milestones in cloud computing history was the arrival of Salesforce.com in 1999, which pioneered the concept of delivering enterprise applications via a simple website.

The next development was Amazon Web Services in 2002, which provided a suite of cloud-based services including storage, computation and even human intelligence through the Amazon Mechanical Turk.

Then in 2006, Amazon launched its Elastic Compute cloud (EC2) as a commercial web service that allows small companies and individuals to rent computers on which to run their own computer applications.

Isolation between organizations and instances

As opposite to Public Cloud (PC) A Virtual Private Cloud (VPC) is an on demand configurable pool of shared computing resources allocated within a public cloud environment, providing certain level of isolation between the different organizations (denoted as users hereafter) using the resources

Cloud computing is about provisioning on-demand computing resources with the simplicity of a mouse click. The amount of resources which can be sourced through cloud computing incorporates almost all the facets of computing from raw processing power to massive storage space.

Amazon Web Services launched Amazon Virtual Private Cloud on 26 August 2009.

Top providers of Public Cloud

AWS
Terremark
SoftLayer (IBM)
Google
Rackspace
Microsoft
OVH

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