Page 67 - Computer - 10(A&B)

operating system allocates the memory when a process requests it to do so and de-allocates the memory when a
process no longer needs it or has been terminated.

Processor Management

In multiprogramming environment, where several programs are running at the same time, the operating
system decides which process gets the processor when and for how much time. This function is called process
scheduling. The operating system keeps tracks of processor and status of processes, allocates the processor
(CPU) to a process, and de-allocates the processor when a process is no longer required.

Device Management

An operating system manages the various hardware devices and communicates with them via their respective
drivers. It keeps track of all the devices connected to the computer, decides which process gets the device, when
and for how much time, allocates the various devices among several programs in the most efficient way, and
de-allocates devices when they are no longer required.

File Management

A file is the basic unit of storage of data on a secondary storage device such as a hard disk or a pen drive. Files
are normally organised into directories or folders for easy navigation and usage. These folders may contain files
and other folders. An operating system keeps track of information about all the files in the computer such as
their size, location, access rights, and status. It provides mechanism for creation of files, insertion of data in the
files, modification of data, and deletion of files. It also decides how the various resources of a computer system
are allocated to various programs for creation of files.

Security
The operating system provides security to a computer by preventing access by unauthorised users. It employs
a system of user identification through passwords and other techniques such as face recognition, finger print
recognition, etc. The operating system prevents unauthorised access to individual programs and files, as well
as to the computer in general.

System Performance Audit
The operating system keeps a track of the performance of the computer system by recording delays between
request for a service and response from the system. This helps the operating system to offer suggestions to the
user for fine-tuning and optimising the functions of the computer.

Error Detection and Reporting
The operating system keeps track of various errors produced during the functioning of the computer system
and generates error messages that let a user understand the problem. It also generates error logs and reports
that a user can examine and send it to others for troubleshooting. The operating system is also responsible for
generating memory and data dumps, in case of system crash, to restore the system to its original state.

Interface Between User and Computer

The most visible function of the operating system is the coordination it provides between the user and the
computer. The operating system provides an interface which lets a user issue commands to the computer to
perform various tasks. It also provides an interface between compilers, interpreters, assemblers, and other
software to the various users.
49