Peripheral devices - output

output devices

Peripheral devices - input

Input devices

Defining the terms

i)Hardware- Hardware is a general term that refers to the physical artifacts of a technology. It may also mean the physical components of a computer system, in the form of computer hardware.

ii)Software- Computer software is a general term used to describe a collection of computer programs, procedures and documentation that perform some tasks on a computer system.

iii)Input device- An Input device is any piece of computer hardware equipment used to provide data and control signals to an information processing system (such as a computer). Input and output devices make up the hardware interface between a computer and the user or external world.

iv)Storage device- A storage device is a device used for storing something.

v)Output device- An output device is any piece of computer hardware equipment used to communicate the results of data processing carried out by an information processing system (such as a computer) to the outside world.

The Mode of Operation

MULTIPROCESSING
Multiprocessing is the use of two or more central processing units (CPUs) within a single computer system. The term also refers to the ability of a system to support more than one processor and/or the ability to allocate tasks between them.[1] There are many variations on this basic theme, and the definition of multiprocessing can vary with context, mostly as a function of how CPUs are defined (multiple cores on one die, multiple chips in one package, multiple packages in one system unit, etc.).

Multiprocessing sometimes refers to the execution of multiple concurrent software processes in a system as opposed to a single process at any one instant. However, the term multiprogramming is more appropriate to describe this concept, which is implemented mostly in software, whereas multiprocessing is more appropriate to describe the use of multiple hardware CPUs. A system can be both multiprocessing and multiprogramming, only one of the two, or neither of the two.

MULTITASKING
In computing, multitasking is a method by which multiple tasks, also known as processes, share common processing resources such as a CPU. In the case of a computer with a single CPU, only one task is said to be running at any point in time, meaning that the CPU is actively executing instructions for that task. Multitasking solves the problem by scheduling which task may be the one running at any given time, and when another waiting task gets a turn. The act of reassigning a CPU from one task to another one is called a context switch. When context switches occur frequently enough the illusion of parallelism is achieved. Even on computers with more than one CPU (called multiprocessor machines), multitasking allows many more tasks to be run than there are CPUs.

BATCH PROCESSING
Batch processing is execution of a series of programs ("jobs") on a computer without human interaction.
Batch jobs are set up so they can be run to completion without human interaction, so all input data is preselected through scripts or commandline parameters. This is in contrast to "online" or interactive programs which prompt the user for such input.

Batch processing has these benefits:
-It allows sharing of computer resources among many users,
-It shifts the time of job processing to when the computing resources are less busy,
-It avoids idling the computing resources with minute-by-minute human interaction and supervision,
-By keeping high overall rate of utilization, it better amortizes the cost of a computer, especially an expensive one.

REAL-TIME PROCESSING
Real-time processing is a process in which when any changes occur in the database, it will be updated instantly. For example, in an airline reservation counter, when people have booked the seats, it will be updated immediately in the database that those seats cannot be taken anymore.

MULTI-USER
Multi-user is a term that defines an operating system or application software that allows concurrent access by multiple users of a computer. Time-sharing systems are multi-user systems. Most batch processing systems for mainframe computers may also be considered "multi-user", to avoid leaving the CPU idle while it waits for I/O operations to complete. However, the term "multitasking" is more common in this context.

reference- www.wikipedia.org

5) Utility Softwares

two examples of it-
Disk defragmenters - Examples include a Disk defragmenter which can detect computer files whose contents have been stored on the hard disk in disjointed fragments, and move the fragments together to increase efficiency; a Disk checker can scan the contents of a hard disk to find files or areas that are corrupted in some way, or were not correctly saved, and eliminate them for a more efficiently operating hard drive; a Disk cleaner can find files that unnecessary to computer operation, or take up considerable amounts of space. Disk cleaner helps the user to decide what to delete when their hard disk is full.

System Profilers - A System profiler can provide detailed information about the software installed and hardware attached to the computer. Backup software can make a copy of all information stored on a computer, and restore either the entire system (e.g. in an event of disk failure) or selected files (e.g. in an event of accidental deletion). Disk compression software can transparently compress the contents of the hard disk, in order to fit more information to the drive.

4) Operating Systems

An operating system (OS) is the software that manages the sharing of the resources of a computer and provides programmers with an interface used to access those resources. An operating system processes system data and user input, and responds by allocating and managing tasks and internal system resources as a service to users and programs of the system. At the foundation of all system software, an operating system performs basic tasks such as controlling and allocating memory, prioritizing system requests, controlling input and output devices, facilitating computer networking and managing files. Most operating systems come with an application that provides an interface for managing the operating system.
2 examples of OS are Windows and Macintosh.

ref- www.wikipedia.org