1. computer
software 2

2. Computer software.
Software, or program, enables a computer to perform specific tasks, as opposed to the physical components of the system (hardware).

3. COMPUTER SOFTWARE
Operating system
Application software
Utilities software

4. Operating system
An operating system (OS) is a computer program that manages the hardware and software resources of a computer.
At the foundation of all system software, an operating system performs basic tasks such as controlling and allocating memory, prioritizing system requests, controlling input and output devices, facilitating networking, and managing files.
It also may provide a graphical user interface for higher level functions. It forms a platform for other software

5. Example :
1. Linux
2. Microsoft Window Vista
3. Red Hat

6. Utilities software
Utility software (also known as service program, service routine, tool, or utility routine) is a type of computer software.
It is specifically designed to help manage and tune the computer hardware, operating system or application software, and perform a single task or a small range of tasks; as opposed to application software which tend to be software suites.
Utility software has long been integrated into most major operating systems.

7. Example:
1. Disk defragmenters
2. System Profilers
3. Virus scanners

8. Application Software
Application software is a subclass of computer software that employs the capabilities of a computer directly to a task that the user wishes to perform.
This should be contrasted with system software which is involved in integrating a computer's various capabilities, but typically does not directly apply them in the performance of tasks that benefit the user.

9. Example :
Microsoft Office
Open office