Cloud computing grew out of the concept of utility computing. Essentially, utility computing was the belief that computing resources and hardware would become a commodity to the point that companies would purchase computing resources from a central pool and pay only for the amount of CPU cycles, RAM, storage and bandwidth that they used. These resources would be metered to allow a pay for what you use model much like you buy electricity from the electric company. This is how it became known as utility computing.
The fundamental concept of cloud computing is that the computing is "in the cloud" i.e. that the processing (and the related data) is not in a specified, known or static place(s). This is in contrast to the traditional computing where the processing takes place in one or more specific servers that are known. However, it must be noted that, the server location, place and controls are still known to someone who is a part in service delivery chain.
Nonetheless, cloud computing is still a complex and dynamic IT Service production and distribution system where different layers of service producing infrastructure are controlled and managed by different entities.
Changing landscape of internal IT Infrastructure
Mainframe based Infra
Enterprise IT infrastructure’s formal first generation started with mainframe era.
Those IT Infrastructures were based on local data center in large corporate office. Hardware of early computer systems was complex to operate and maintain, and required a special environment in which to operate. Many cables were necessary to connect all the components and methods to accommodate and organize these were devised, such as standard racks to mount equipment, elevated floors, and cable trays (installed overhead or under the elevated floor). Also, old computers required a great deal of power, and had to be cooled to avoid overheating. Security was important – computers were expensive, and were often used for military purposes.
Basic design guidelines for controlling access to the computer room were therefore devised.
Heterogeneous Server based Infra
With the advent of client-server computing, during the 1990s, "servers" started to find their places in the old computer rooms. The availability of inexpensive networking equipment, coupled with new standards for network cabling, made it possible to use a hierarchical design that put the servers in a specific room inside the company. The use of the term "data center," as applied to specially designed computer rooms, started to gain popular recognition about this time.
The boom of datacenter hosting came during the dot-com bubble. Companies needed fast Internet connectivity and nonstop operation to deploy systems and establish a presence on the Internet. Installing such equipment was not viable for many smaller companies. Many companies started building very large facilities, called Internet data.