(i) Air traffic Control System, where at any moment the user must know the latest information to take further action.
(ii) Updating of a bank account of a customer to know the various transactions and balance to go for the next action.

(i) An OS is required to access and use the hardware resources.
(ii) It provides a stable, consistent way for applications to deal with the hardware.
(iii) An OS prepares the computer for taking instructions from the user and converts into machine code and gives into the CPU for execution.
(iv) as only co-ordinates and controls all the activities of a computer system.

(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) Any type of data in a computer is stored in the form of files and directories/folders through File Allocation Table (FAT).
(ii) The FAT stores general information about files like filename, type(text or binary), size, starting address and access mode (sequential/indexed sequential /direct/relative).

(i) Each program or task is given a fixed amount of time to execute.
(ii) The CPU continues with the execution till either the allotted time is over or there is some interrupt request or the task is completed before the allotted time.

(i) Farmers
(ii) Response time
(iii) Throughput
(iv) Turn around time

(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).

(i) Multiprocessing is the use of two or more CPUs within a single computer system.
(ii) A system is said to be multiprocessing if it has more than one physical processors. Since it has multiple processors available, multiple processes can be executed at a time.
(iii) In Multiprocessing, processes can be assigned to a different processor for its execution.
(iv) With the help of multiprocessing system more work can be done in a shorter period of time.
(v) Multiprocessing system provides increased reliability means that if one processor fails, the other processor will continue its working. For example, if there are10 processors and 1 fails then the work does not halt, instead the remaining 9 processor will share the work of 10 th processor.
(vi) Multiprocessing system increases the Throughput i.e. if we increase the number of processors, more work can be completed.
(vii) As multiprocessing occurs by parallel processing, it is cost saving since it parallelly shares memory, buses, peripherals, etc.
(viii) Multiprocessor refers to hardware (CPU units) rather than software (running programs).

User interface:
(i) It is one of the important features of an Operating system.
(ii) User interface allows user to interact with computer effectively.
(iii) An interactive Operating system provides astonishing feature of Graphical User Interface.
(iv) GUI is one of the advanced features that have made Windows and other interactive Operating system highly popular.
(v) Some properties of GUI are display of icons, movement of cursor, etc.
Memory Management:
(i) Operating system performs the function of memory management. Memory Management is the process of controlling and coordinating with computers main memory.
(ii) The Operating system keeps a track of main memory/primary memory i.e. which portion of memory is currently being used and who is using them.
(iii) Memory Management involves allocation and de-allocation of memory blocks.
File Management:
(i) File Management is an important function of Operating System that maintains and manages file operation.
(ii) File Management manages files, folder and directory system on computer.
(iii) The process of File Management includes creating, modifying and deleting of files.
(iv) File Management of Operating system helps to create new files and place them at specific location and makes the process of sharing of files easy.
Process Management:
(i) Process Management includes creation and deletion of processes.
(ii) Process Management provides mechanism for communication and synchronization of processes.
I/O Management:
(i) The Operating system is responsible for all sorts of input from keyboard, mouse, desktop, etc.
(ii) Operating system effectively handle I/O operation to hide the peculiar behavior from the end-user.
Security Management:
(i) Operating system provides security by protecting unauthorize access to computer and uses password and other similar technique to protect user data

Time-Sharing Operating Systems
Advantages	Disadvantages
Provides the advantage of quick response.	Problem of reliability.
Avoids duplication of software.	Questions of security and integrity of uses programs and data
Reduces CPU idle time.	Problem of data communication.