COMPUTER SOFTWARE

  1.1            System Software

System software is computer software or an operating system designed to operate and control the computer hardware and to provide a platform for running application software.

1.1.1 Operating System (OS)

An operating system (OS) is a collection of software that manages computer hardware resources and provides common services for computer programs. The operating system is a vital component of the system software in a computer system. Application programs require an operating system to function.

                  

1.1.1.1 Real-time

A real-time operating system is a multitasking operating system that aims at executing real-time applications. Real-time operating systems often use specialized scheduling algorithms so that they can achieve a deterministic nature of behavior. The main objective of real-time operating systems is their quick and predictable response to events. They have an event-driven or time-sharing design and often aspects of both. An event-driven system switches between tasks based on their priorities or external events while time-sharing operating systems switch tasks based on clock interrupts.

             

1.1.1.2 Multi-user

A multi-user operating system allows multiple users to access a computer system at the same time. Time-sharing systems and Internet servers can be classified as multi-user systems as they enable multiple-user access to a computer through the sharing of time. Single-user operating systems have only one user but may allow multiple programs to run at the same time.

 1.1.1.3 Distributed

A distributed operating system manages a group of independent computers and makes them appear to be a single computer. The development of networked computers that could be linked and communicate with each other gave rise to distributed computing. Distributed computations are carried out on more than one machine. When computers in a group work in cooperation, they make a distributed system.

1.1.1.4 Embedded

Embedded operating systems are designed to be used in embedded computer systems. They are designed to operate on small machines like PDAs with less autonomy. They are able to operate with a limited number of resources. They are very compact and extremely efficient by design. Windows CE and Minix 3 are some examples of embedded operating systems.

          1.1.2 Language Translator

                   It converts human language into binary language.

          1.1.3 Utility Software

                   Utility Software is a set of programs that manages and maintain computer peripherals and accessories.

1.2 Application Software

This is also known as an application or an app, is computer software designed to help the user to perform specific tasks. Examples include enterprise software, accounting software, office suites, and graphics software and media players. Many application programs deal principally with documents. Applications may be bundled with the computer and its system software, or may be published separately. In recent years, the abbreviation "app" has specifically come to mean application software written for mobile devices, with the abbreviation in particular representing both the smaller size and smaller scope of the software (i.e. an app whose sole purpose is to display an image representation of the current weather). Apps for mobile devices are also an important way to deliver advertising to the user. Many websites encourage mobile users to download a free app version of the website so that they can receive cut down advertising typically as a row along the bottom of the app as stock mobile web browsers often do not display the adverts available on full size websites.

COMPUTER HARDWARE

2.1 Input Devices

          Input devices allow the user to enter information into the system, or control its operation. Very early computer systems had literal toggle switches that could be tested by running programs as a simple form of user input; modern personal computers have alphanumeric keyboards and pointing devices to allow the user to interact with running software.

Examples: keyboard, mouse, joystick, webcam, image scanner, microphone

2.1.1 Processing Devices

          Processing devices in a computer are responsible for controlling the storage and retrieval of information. The information is processed by the computer processor (CPU), which performs data calculations, data comparisons, and data copying with the information from the processing devices. The CPU then saves that information to the computer memory (RAM).

Today's computers contain multiple processing devices. Any device that deals with the input and output of information does some form of processing on that information, some with more complexity than others. The one processing device that most people think of is the CPU, but devices like the graphics card, computer memory, network card, and others are processing devices as well.

Example: CPU, MpU (Micro processing Unit), McU (Micro controller Unit)

2.1.2 Storage Devices

          Computer data storage, often called storage or memory, refers to computer components and recording media that retain digital data. Data storage is a core function and fundamental component of computers.

Examples: CD, DVD, Pen Drive, Memory Card

2.1.3  Output Devices

          Output devices display information in a human readable form. A program-controlled pilot lamp would be a very simple example of an output device. Modern personal computers have full-screen point-addressable graphic displays and often a printing device to produce paper copies of documents and images.

Examples: monitor, printer, speakers, projector

 

2.1.4 Input/output Devices

          Alternatively referred to as an IO device, an input/output device is a hardware device that accepts inputted information and also has the capability of outputting that information. 

Examples: digital camera, cell phone, all-in-one printer