The security modules of an Operating System protect the resources and information of a computer system against destruction and unauthorized user access. It is a process of ensuring OS integrity, confidentiality and availability.

This feature helps to recording delays between request for a service and response from the distributed or parallel computer system. It helps to monitoring system performance in various situations to resolves the problems and finds the root cause of the reported Issues.

The memory management techniques are
(i) Single contiguous allocation.
(ii) Partitioned allocation
(iii) Paged Memory Management
(iv) Segmented Memory Management.

Segments require hardware support in the form of a segment table which usually contains the physical address of the segment in memory, its size, and other data such as access protection bits and status (swapped in, swapped out, etc.)

(i) An as is a system software which serves as the interface between a user and computer.
(ii) It is defined as a collection of programs that coordinates the operations of computer hardware and software.
(iii) On the basis of interaction, the Operating systems are divided in two types as GUI and CUI.

(i) This is the operating system that provides a Graphic User Interface (GUI) through which the user can easily navigate and interact.
(ii) The computer responds almost immediately after an instruction has been entered, and the user can enter new instructions after seeing the results of the previous instructions.

(i) This algorithm is based on queuing technique. This is the basic logic of the FIFO algorithm.
(ii) Technically, the process that enters the queue first is executed first by the CPU, followed by the next and so on.
(iii) The processes are executed in the order of the queue (row).

A mobile operating system controls a mobile device and its design supports wireless communication and different types of mobile applications. It operates on smart phones Tablets and Digital Mobile devices.
(i) Google Android
(ii) Apple iOS
(iii) Blackberry
(iv) Symbian

Advantages and disadvantages of Time Sharing Option (TSO)