Three layers of computing


At a basic level when you use a personal computer you interact with three layers of computing. First, at the lowest layer, you have a physical piece of hardware with its processors, memory chips, disk drives, network cards and other components – we can call this the infrastructure. Second, in the middle layer, you have an operating system (such as Microsoft Windows) that interacts with the hardware and  provides a consistent environment for running and developing software (using Visual Basic or Microsoft Access, for example) if you wish – we can call this the platform. And finally, at the top, there are third-party software applications (such as word processing packages) that you use in your work and play – and we can call these software. Figure 1.1

simple three-layer pyramid model

depicts this three-layer model of computing as a pyramid with infrastructure at the bottom, the platform in the middle
and software at the top.

Now consider a computer network for an office-based business that manages its own IT systems. To run this network
the business would typically require system administrators to look after hardware and networking (infrastructure);
IT support staff and desktop deployment tools to install applications and update the operating systems (platforms)
on desktop computers; and users who perform tasks with these applications (software).

This three-layer model can be applied to cloud computing, too, but there are a few key differences:

  • Software applications are not desktop applications – they are web-based so they can be used in any up-to-date web browser on any computer operating system.
  • Platforms are purpose-built software development environments that are hosted on the internet rather than your desktop computer so all you need is a web browser to create, test and deploy web applications.
  • Infrastructure elements (servers, storage, bandwidth, processing power, etc) are provided by a third party; but you can access and use these computing resources as if they were installed on your own corporate network.

Like Michael Sheehan, who first proposed a ‘cloud pyramid’, I find the three-layer model useful for differentiating
between cloud computing service offerings (Sheehan, 2008).



  1. Youre so cool! I dont suppose Ive learn something like this before. So nice to search out someone with some authentic thoughts on this subject. realy thanks for beginning this up. this web site is something that is needed on the web, someone with a bit originality. useful job for bringing one thing new to the web!

Comments are closed.