Introduction to information systems T. Cornford, M. Shaikh is1 060 2013

Activity
Find and describe three examples of client-server computing. 
In each case, try to explain why this approach is used (for example, the benefits it brings) 
and what tasks (processing, data storage, etc.) are handled by the client and by the 
server. 
Research the benefits and problems of using a commercial cloud service to provide 
computing resources for a medium sized business. Think in each case (both for benefits 
and problems) about issues associated with cost, control, security and flexibility. Do you 
imagine that one day almost all computing will be provided in this way?
4.3 Software: operating systems and applications
Computers require programs (software) in order to run; the computer 
hardware described above can do nothing useful unless it has some 
instructions to follow − some software. It is usual to differentiate between 
systems software, which helps the machine to operate, and applications 
software, which directly performs some useful task for those using the 
computer (for example, Microsoft Windows is an operating system; 
Microsoft Word is an application).

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IS1060 Introduction to information systems
52
Reading activity
Read Section 3.3 of Curtis and Cobham (2008).
The operating system is the principal item of systems software. It is 
described in some detail here, because studying the operating system is a 
useful way to understand the nature and functions of computer hardware. 
The operating system manages the hardware resources of the computer 
and organises the running of programs. It also provides the user with the 
means of controlling the computer, and a computer user communicates 
with the operating system in order to get the computer to undertake any 
task − for example, to run a program or print a file. In most of today’s 
operating systems, this user interface is based on the WIMP (window, icon, 
mouse, pull-down menu) concept, which combines these four features for 
effective communication with the user. Apple OS and Microsoft Windows 
are examples of operating systems that provide a common, consistent and 
sophisticated graphical user interface (GUI) for application programs to 
use. Linux is an example of an open source operating system developed by 
volunteers and freely available as source code, and users of Linux have a 
choice as to the style of interface they use.
All computers from phones to science GRIDs require an operating system 
of some description. One way to view the main task of an operating 
system is as allowing the initiation and running of other application 
programs. When someone wishes to run a program – for example, a 
spreadsheet – they tell the operating system the name of the program (by 
pointing and clicking) and ask that it be run. In order to run the program 
the operating system needs to manage and coordinate the hardware, 
software and network resources. We can think of these as six separate, but 
connected types of resource:
• memory management
• input–output management
• secondary storage management
• processor management
• program management
• network management.