First Term


Week 4




Previous lesson:

Pupils have previous knowledge of




that was taught in their previous lesson






Behavioural objectives:

At the end of the lesson, the pupils should be able to


  • say the meaning of the operating software
  • mention types of operating software
  • explain the uses of operating system


Instructional Materials:

  • Wall charts
  • Pictures
  • Related Online Video
  • Flash Cards

Methods of Teaching:

  • Class Discussion
  • Group Discussion
  • Asking Questions
  • Explanation
  • Role Modelling
  • Role Delegation


Reference Materials:

  • Scheme of Work
  • Online Information
  • Textbooks
  • Workbooks
  • 9 Year Basic Education Curriculum
  • Workbooks





There are different types of operating system as specified by their operational performance. The most commonly used operating systems are:

  1. Single user Operating System
  2. Multi User Operating System
  3. Distributed Operating System
  4. Multiprocessing Operating System


  1. Single User Operating System:

Types of Single User OS:

(i) Single User/Single Tasking OS: This allows only a single task performed at a time. It allows a single user to operate the machine at a time in an interactive mode and allows one user program to be in the main store and processed at a time. It does not allow users program. Examples of a single user operating system include Palm OS for Palm handheld computers.

(ii) Single User/Multitasking OS: This allows several programs to run at the same time by a single user. Example is Window 95, Windows NT, Workstation and Windows 2000 professional.


  1. Multi-User Operating System:

Multi-user operating system has been designed for more than one user to access the computer at the same or different time. It permits the execution of more than one task at a time. It shares the system resources to more than one user by connecting the individual user on the system.

(i) Time Sharing OS

(ii) Batch Processing OS

These operating systems are types of Multi-user OS in which CPU time is divided among the users. The division is made on the basis of a schedule.

Examples are UNIX, Linux.


  1. Distributed Operating System:

Distributed operating system manages a group of distinct computers and make them appear to be a single computer. This is where distributed applications are running on multiple computers linked together communications. A distributed operating system is an extension of the network operating system that supports higher levels of communication and interaction of the machine on the network. Distributed computations are carried out on more than one computer machine. When computers in a group work in cooperation, they form a distributed system. The computers involved in the use of this OS communicate through LAN / WAN network. Examples of Distributed OS are internet and Intranet (the portion of the internet which is managed by an organization).


  1. Multiprocessing Operating System: 

Multiprocessing operating system is the operating system that supports the use of two or more central processing unit (CPU’s) within a single computer system. It also refers to the ability of an operating system to support more than one processor or the ability to allocate tasks between them. Examples of multi-processing operating systems are Windows NT, 2000, XP, and UNIX.



  1. State 5 examples of operating system
  2. List the types of operating system
  3. Explain any TWO types of operating system
  4. Highlight two examples of each of the types of operating system

Function of the Operating System

The following are the functions of the operating system:

(i) Resource Allocation: Operating system allocates computer resources such as CPU time, main memory (RAM), secondary storage and input and output devices for use.

(ii) File Management: It helps in the transfer of file from one storage devices to another. It also allows all files to be easily changed and modified through the use of text editors or some other file manipulating software.

(iii) Memory Management: It allows the allocation of the main memory and other storage areas to the system programs as well as user programs and data.

(iv) It Interprets commands and instructions

(v) It coordinates and assigns compilers, assemblers, utility programs and other software to the various users of the computer system.

(vi) System Monitoring: Operating system monitors jobs submitted for executions to ensure efficient processing.

(vii) Input/output management: it assigns different input and output device while one or more programs are being executed.

(viii) It facilitates easy communication between the computer system and the computer operator.

(ix) It performs automatic transition from job to job as directed by special control statement.

(x) It determines and maintains the order in which jobs are to be executed in the computer system.

The functions of the operating system

1. The operating system provides a platform for applications to run on.
2. The operating system manages the resources of the computer.
3. The operating system provides basic services to applications.
4. The operating system handles input and output operations.
5. The operating system manages files and folders on the computer


1. To manage and control devices attached to the computer
2. To provide a platform for software applications
3. To store data and programs
4. To allow communication between users and the computer
5. To protect the computer from unauthorized access


The topic is presented step by step

Step 1:

The class teacher revises the previous topics


Step 2:

He introduces the new topic


Step 3:

The class teacher allows the pupils to give their own examples and he corrects them when the needs arise




1. What is the purpose of system software? Mention two
2. How does system software work? Briefly explain in not more than 50 words.
3. What are the different types of system software?
4. Why is it important to have system software?
5. Can you think of an example of a situation where system software would be used?




The class teacher wraps up or concludes the lesson by giving out a short note to summarize the topic that he or she has just taught.

The class teacher also goes round to make sure that the notes are well copied or well written by the pupils.

He or she makes the necessary corrections when and where the needs arise.