What is Really New About the Cloud?
23.05.12
To understand what is new, it's first important to understand the origins of the term "cloud". In the late 1990s, as it was becoming clear that the Internet would change virtually everything in the world of information technology, people began to draw system architecture diagrams using a picture of a cloud to represent the Internet.
This was important, because the ability of one computer system to connect to another without having established a separate electronic link (via wire, telephony modem, or otherwise) was completely new. Previously, architecture diagrams would include the explicit connections and the physical devices involved. Now connectivity was just an abstraction, and a relatively reliable connection could be assumed without details.
At that stage, putting a system "in the cloud" just meant that it was persistently available on the public Internet. That is still true today, which is the source of Larry Ellison's notoriously dismissive comment "cloud computing is just a computer attached to a network."
Source: ReadWriteWeb