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In this video we going to talk about cloud computing now most of us are familiar with the concept of

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running an operating system on a P.C..

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So as an example I've got a Windows 7 P.C..

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This is a Windows 7 operating system installed on a physical server.

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I'm connecting to that Windows P.C. using Microsoft remote desktop and I'm using a Mac for these recordings.

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So I've got a Mac and I'm running Janus 3 as an example locally on my Mac.

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Now in the same way that operating systems are installed on laptops and PS servers in the past we have

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physical pieces that you would install operating systems on and you would run applications on individual

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physical servers.

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So as an example if you wanted a e-mail server you would order a physical server you'd install the Windows

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operating system and then you would install exchange and configure Exchange to give you email if you

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wanted to file server you would order a physical server then you would install Windows on it and then

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you would store your files on that physical server if you wanted a web server you would order a third

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server install an operating system such as Linux or Windows on that server and then run a web server

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using ISIS or Apache.

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So in the past companies had physical servers and in many cases it was one server per function if you

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needed a file server an email server a web server a database server etc. you would buy a physical server

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per application and if you needed more capacity you would buy more physical servers.

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Now in many cases that's inefficient.

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Not all applications require all the memory and all the CPSU on a physical P.C. all the time.

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So for a number of years there's been a trend to virtualization.

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In other words you virtualize the operating system in what are called virtual machines rather than running

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individual operating systems on bare metal or physical pieces.

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You run operating systems in virtual machines and you host multiple servers virtually on a single physical

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server.