Operating System (OS)
OS are a set of programs that monitor and co-ordinate software and hardware within a computer system. Operating systems are the most important programs and must be present in all computer systems for other programs to run. Examples of OS are Windows, UNIX, Linux, Unix, Mac OS and DOS.
Functions of the Operating System
The OS is needed in a computer system to perform the following main functions:
- Process management
- File management
- Memory management
- input/output device management
- provide security
- provide a friendly user interface
Process management
A program that is running can be considered as a process and a program can have many sub-programs. Therefore, many processes would occur in a computer system when a program is being executed. The process management function of the OS involves allocating adequate time and resources of the Central Processing Unit (CPU) to each process.
File management
All the files created in secondary storage media, such as the hard disk, are stored within its various files. The OS is responsible for creating, deleting, renaming of files and folders and also making back-up copies of files.
Memory Management
Main memory or RAM stores programs and data that are presently being used by the CPU. The OS allocates areas of memory to different programs so that each program can function effectively.
Input/Output device management
There are many peripheral devices such as keyboards, mouse and monitors that can be connected to the system unit. The OS makes the communication possible between the peripheral devices and the system unit.
Provide security
Modern computer systems require the entry of a password in order to access the system. The operating system provides the user with password protection to prevent unauthorised access. It also provides back-up and recovery routines in case of system failure.
Provide a friendly user interface
The method by which user interacts with a computer system is called user interface. The OS provides the user with a friendly interface that will help the user to interact with the computer system. For example, if your computer has a Windows OS you will see a desktop from which you can interact with the computer system. Both systems software and application software have user interfaces.
Reference
SCHS Information Technology Blog 