What is the Cloud
The term "cloud" is used as a metaphor for the Internet, based on the cloud drawing
used in the past to represent the telephone network,
and later to depict the Internet in
computer network diagrams as an
abstraction of the underlying infrastructure it represents.
Cloud computing is a natural evolution of the widespread adoption of
utility computing. Details are abstracted from
end-users, who no longer have need for expertise in, or control over, the
technology infrastructure "in the cloud" that supports them.
The underlying concept of cloud computing dates back to the 1960s, when
John McCarthy opined that
"computation may someday be organized as a
public utility." Almost all the modern-day characteristics of cloud
computing (elastic provision, provided as a utility, online, illusion of
infinite supply), the comparison to the electricity industry and the use of
public, private, government, and community forms, were thoroughly explored in
Douglas Parkhill's 1966 book, The Challenge
of the Computer Utility.
The actual term "cloud" borrows from
in that telecommunications companies, who until the 1990s offered primarily
dedicated point-to-point data circuits, began offering Virtual Private Network (VPN) services
with comparable quality of service but at a much lower cost. By switching
traffic to balance utilization as they saw fit, they were able to utilize their
overall network bandwidth more effectively. The cloud symbol was used to denote
the demarcation point between that which was the responsibility of the provider
and that which was the responsibility of the user. Cloud computing extends this
boundary to cover servers as well as the network infrastructure.
After the dot-com bubble,
played a key role in the development of cloud computing by modernizing their
centers, which, like most
computer networks, were using as little as 10% of their capacity at any one
time, just to leave room for occasional spikes. Having found that the new cloud
architecture resulted in significant internal efficiency improvements whereby
small, fast-moving "two-pizza teams" could add new features faster and more
easily, Amazon initiated a new product development effort to provide cloud
computing to external customers, and launched
Amazon Web Service (AWS) on a
utility computing basis in 2006.