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Cloud Computing

Notes Draft of Web-hosted, group collaborative, Internet-accessible applications are currently available,
with many more on the way.

Example: The most popular examples of cloud computing applications today are the
Google family of applications like Google Docs Spreadsheets, Gmail, Google Calendar, Picasa,
etc. These are the best examples of cloud computing.
All of these applications available on Google’s servers can be accessed by any user having an
Internet connection. It can also be used for group collaboration and associations from anywhere
in the world.

Cloud computing thus encourages a shift from the computer to the user, from applications to
tasks, and from isolated and restricted data to data and information that can be accessed from
anywhere in the world and can be shared with everyone. With this facility of cloud computing,
the user need not take on the task of data management on its shoulder. In fact, the user need not
even remember where the data is, since, even that can be easily accessed. However, one must
remember that this data should be in the cloud only then can it be accessed, and be immediately
available to that user and to other authorized user.

1.2 History of Cloud Computing

Cloud computing has its ancestors both as client/server computing and peer-to-peer distributed
computing. It is all about how centralized storage of data and content facilitates collaborations,
associations and partnerships. Here, it is also essential to know how multiple computers work
together as a unit and increase computing power.

1.2.1 Client/Server Computing: Centralized Applications and Storage

Everything was operated on the client/server model in ancient days of computing. Back then
huge mainframe computers called servers where home to all the controls, all the software and
all significant information and other relevant data. The user back then had to connect to the
mainframe, gain appropriate access, and then do business while essentially “renting” the program
or data from the server, in case the user wanted to access specific data or run a specific program.

Users usually connected to the server via a computer terminal, also referred to as the client or
the workstation. Due to the lack of any storage space, memory and processing power, this
computer was many a times called a dumb terminal. It was nothing more than a device that
connected the user to the mainframe computer and enabled him to use it.
Only when granted permission could the users access the mainframe. The IT staff was, however,
always careful while handing out access. Processing power is limited even on the mainframe
computer. The IT staff guarded that power. Two users could not access the same data at that
specific time and this access was not immediate.
Beyond that, users pretty much had to take whatever the IT staff gave them with no variations.
Want to customize a report to show only a subset of the normal information? Cannot do it. Want
to create a new report to look at some new data? You cannot do it, although the IT staff can, but
on their schedule, which might take weeks from now.
When multiple people are sharing a single computer, even if that computer is a huge mainframe,
you have to wait your turn. Need to rerun a financial report. There is not always immediate
access in a client/server environment, and seldom is there immediate gratification.
So the client/server model, while providing similar centralized storage, differed from cloud
computing in that it did not have a user-centric focus; with client/server computing, all the

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