Page 24 - Computer Science V2.0 Class 11

System Software
System Software provides basic functionality to operate a computer. Examples of system software are operating
systems, utilities, device drivers, and compilers.

Operating System

An operating system provides an interface between the users of a computer and the computer hardware so that they
can operate the computer. The operating system software also manages all other software installed on the computer
system. Some examples of the operating system are Microsoft Office, LibreOffice, UNIX, and DOS.
Functions of Operating System

An operating system performs several functions like management of memory, process, file, and device. In the following
paragraphs, we describe each of these operating system functions briefly:

Memory Management
An operating system is responsible for allocating memory to different processes for their execution and claiming it back
when the execution of a process is over so that it can be allocated to other processes.

Process Management

Nowadays, a computer may have several independent processors that execute several programs in parallel. But even
if a computer has only a single CPU, it may still work on several programs simultaneously. A program whose execution
has been initiated but not yet over is called a process. The operating system manages efficient execution of all the
processes so that each of them gets access to system resources such as CPU time, memory, and I/O devices. The
operating system also ensures a smooth exchange of information between various processes.

A program whose execution has been initiated but is not yet over is called a process.

File Management

Data is stored as files on a computer. The operating system monitors the creation, deletion, or any form of modification
of data of these files. Protecting the files against unauthorised access is an important operating system function. With
multiple users accessing the same system and applications, the operating system manages the access permissions of
all files on the computer.

Device Management

The operating system manages the devices installed on a computer system. It also enables the installation and
configuring of new devices on the computer. It ensures that only the authorised users are allowed to access various
devices.

System Utilities
A system utility helps in the smooth functioning of the system. For example, a disk cleanup utility helps to remove
unwanted files that are no more required but might have been created for short-term use by some programs. Also,
there may be some files that a user has deleted, but they continue to occupy space in the bin (in the hope that some
of them may need to be recovered again in case it is found that the files were still useful but deleted by mistake).
Similarly, a defragmentation utility reorganises the disk space for efficient use. A backup utility enables us to store the
current software version or data for possible future use, maybe on a separate disk. While the aforementioned utilities
are often bundled with the operating system, others may be priced. For example, the utility WinZip 24.0, meant for
compressing data, is priced except for a trial version.

10 Touchpad Computer Science (Ver. 2.0)-XI