Computer Software

Computer software, or just software, is a collection of computer programs and related data that provide the instructions for telling a computer what to do and how to do it. In other words, software is a conceptual entity which is a set of computer programs, procedures, and associated documentation concerned with the operation of a data processing system. We can also say software refers to one or more computer programs and data held in the storage of the computer for some purposes. In other words software is a set of programs, procedures, algorithms and its documentation. Program software performs the function of the program it implements, either by directly providing instructions to the computer hardware or by serving as input to another piece of software.


System Software

System software provides the basic functions for computer usage and helps run the computer hardware and system. It includes a combination of the following:

• Device drivers
• Operating systems
• Servers
• Utilities
• Window systems

System software is responsible for managing a variety of independent hardware components, so that they can work together harmoniously. Its purpose is to unburden the application software programmer from the often complex details of the particular computer being used, including such accessories as communications devices, printers, device readers, displays and keyboards, and also to partition the computer's resources such as memory and processor time in a safe and stable manner.


Programming software
Programming software usually provides tools to assist a programmer in writing computer programs, and software using different programming languages in a more convenient way. The tools include:

• Compilers
• Debuggers
• Interpreters
• Linkers
• Text editors

An Integrated development environment (IDE) is a single application that attempts to manage all these functions.


Application software 

Application software is developed to perform in any task that benefits from computation. It is a broad category, and encompasses software of many kinds, including the internet browser being used to display this page. This category includes:

• Business software
• Computer-aided design
• Databases
• Decision making software
• Educational software
• Image editing
• Industrial automation
• Mathematical software
• Medical software
• Molecular modeling software
• Quantum chemistry and solid state physics software
• Simulation software
• Spreadsheets
• Telecommunications (i.e., the Internet and everything that flows on it)
• Video editing software
• Video games
• Word processing

Hardware: Output Devices

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.
In computing, input/output, or I/O, refers to the communication between an information processing system (such as a computer), and the outside world. Inputs are the signals or data sent to the system, and outputs are the signals or data sent by the system to the outside.

Some of the Output Devices

Display Devices
A display device is an output device for presentation of information in visual or tactile form (the latter used for example in tactile electronic displays for blind people). When the input information is supplied as an electrical signal, the display is called an electronic display.The Most common form of display devices are the Computer Monitors.


Printers
In computing, a printer is a peripheral which produces a text or graphics of documents stored in electronic form, usually on physical print media such as paper or transparencies. Many printers are primarily used as local peripherals, and are attached by a printer cable or, in most new printers, a USB cable to a computer which serves as a document source.
Impact Printer
Impact printers rely on a forcible impact to transfer ink to the media, similar to the action of a typewriter. The impact printer uses a print head that hits the surface of the ink ribbon, which presses the ink onto the paper. All but the dot matrix printer rely on the use of formed characters, letterforms that represent each of the characters that the printer was capable of printing.
Non Impact Printers
Pen-based plotters were an alternate printing technology once common in engineering and architectural firms. Pen-based plotters rely on contact with the paper (but not impact, per se) and special purpose pens that are mechanically run over the paper to create text and images.
Thermal Printers
Thermal printers work by selectively heating regions of special heat-sensitive paper. Monochrome thermal printers are used in cash registers, ATMs, gasoline dispensers and some older inexpensive fax machines. Colours can be achieved with special papers and different temperatures and heating rates for different colours; these coloured sheets are not required in black-and-white output. One example is the ZINK technology.
Mobile Printers
Mobile Printers are hand held small and portable printers.


Audio Output Devices
Any devices that allow the computer to play audio is an audio audio output device. The most common form of audio output devices are computer speakers.


Other Forms of Output Devices

• Data projector
• Force feedback,etc....

Hardware: Input Devices

In computing, an input device is any peripheral (piece of computer hardware equipment) used to provide data and control signals to an information processing system such as a computer or other information appliance. Input and output devices make up the hardware interface between a computer and a scanner or 6DOF controller.

Keyboard
In computing, a keyboard is a typewriter-style keyboard, which uses an arrangement of buttons or keys, to act as mechanical levers or electronic switches. Following the decline of punch cards and paper tape, interaction via teleprinter-style keyboards became the main input device for computers.


Pointing Devices
A pointing device is an input interface (specifically a human interface device) that allows a user to input spatial (i.e., continuous and multi-dimensional) data to a computer. CAD systems and graphical user interfaces (GUI) allow the user to control and provide data to the computer using physical gestures — point, click, and drag — for example, by moving a hand-held mouse across the surface of the physical desktop and activating switches on the mouse. Movements of the pointing device are echoed on the screen by movements of the pointer (or cursor) and other visual changes. eg. Computer mouse and touch pads, etc.


Game Controllers
A game controller is a device used with games or entertainment systems used to control a playable character or object, or otherwise provide input in a video game. A controller is typically connected to a game console or computer by means of a wire, cord or nowadays, by means of wireless connection. Controllers which have been classified as game controllers are keyboards, mice, game pads, joysticks, etc.


Voice Input Devices
Voice input computer systems (or speech recognition systems) learn how a particular user pronounces words and uses information about these speech patterns to guess what words are being spoken.  


Imaging and Video Input Devices
Video input devices are used to digitize images or video from the outside world into the computer. The information can be stored in a multitude of formats depending on the user's requirement.
OCR
Optical character recognition, usually abbreviated to OCR, is the mechanical or electronic translation of scanned images of handwritten, typewritten or printed text into machine-encoded text. It is widely used to convert books and documents into electronic files, to computerize a record-keeping system in an office, or to publish the text on a website. OCR makes it possible to edit the text, search for a word or phrase, store it more compactly, display or print a copy free of scanning artifacts, and apply techniques such as machine translation, text-to-speech and text mining to it.
OMR
Optical Mark Recognition (also called Optical Mark Reading and OMR) is the process of capturing human-marked data from document forms such as surveys and tests.
Barcodes
A barcode is an optical machine-readable representation of data, which shows data about the object to which it attaches. Originally barcodes represented data by varying the widths and spacings of parallel lines, and may be referred to as linear or 1 dimensional (1D). Later they evolved into rectangles, dots, hexagons and other geometric patterns in 2 dimensions (2D). Although 2D systems use a variety of symbols, they are generally referred to as barcodes as well. Barcodes originally were scanned by special optical scanners called barcode readers; later, scanners and interpretive software became available on devices including desktop printers and smartphones.
RFID
Radio-frequency identification (RFID) is a technology that uses radio waves to transfer data from an electronic tag, called RFID tag or label, attached to an object, through a reader for the purpose of identifying and tracking the object. Some RFID tags can be read from several meters away and beyond the line of sight of the reader. The application of bulk reading enables an almost-parallel reading of tags.
Magnetic Stripe Card
A magnetic stripe card is a type of card capable of storing data by modifying the magnetism of tiny iron-based magnetic particles on a band of magnetic material on the card. The magnetic stripe, sometimes called swipe card or magstripe, is read by physical contact and swiping past a magnetic reading head.
MICR
Magnetic Ink Character Recognition, or MICR, is a character recognition technology used primarily by the banking industry to facilitate the processing of cheques and makes up the routing number and account number at the bottom of a check. The technology allows computers to read information (such as account numbers) off printed documents. Unlike barcodes or similar technologies, however, MICR codes can be easily read by humans.


Biometric Input
Biometric input is a fed in by a device designed to measure certain physical qualities, such as facial recognition, fingerprint recognition, handprint recognition, or any other type of system that can reasonably identify one person from the rest of the people living in the world, and often replaces or supplements traditional passwords.


Terminals
A computer terminal is an electronic or electro mechanical hardware device that is used for entering data into, and displaying data from, a computer or a computing system. Some exaples of terminals are

• POS Systems
• ATMs
• KIOSKs

Hardware: System Unit

System Unit (Case)

Black Zalman GT1000 Gaming Casing

The system unit is a case that contains the electronic components ( Processor, motherboard and expansion cards) and most storage units in a computer.

System unit Components

• Motherboard
• Processor
• Memory Modules
• Expansion Cards
• Sound
• Modem
• Video
• Network Interface Cards

Motherboard

a motherboard is the central printed circuit board (PCB) in many modern computers and holds many of the crucial components of the system, providing connectors for other peripherals. 


Central Processing Unit (CPU)

Intel Core(TM) i7 Processor

• Memory + Processor = CPU.
• Sometimes the processor itself is also referred to as CPU.
• It converts data into information
• It is the Control Center

Architecture of CPU

The Architecture of a CPU

Control Unit (CU)

The hardware that is in charge  and directs the computer system to execute stored program instructions and communicates with other parts of the hardware.
Arithmetic Logic Unit (ALU)
Performs arithmetical operations such as addition,subtraction, multiplication division and also logical and relational comparison operations like AND, OR, NOT,=,<,>.
Registers
Registers are special purpose, high speed temporary storage located inside the CPU.


Main Memory

• RAM (Random Access Memory)
• ROM (Read Only Memory)

RAM (Random Access Memory)

It holds the program instructions and the data that is being used by the processor, most types of RAM are volatile and could not resist the data in them when power is cut off.There are two types of RAM

• DRAM (Dynamic  Random Access Memory )
• SRAM (Static  Random Access Memory )

ROM (Read Only Memory)

It holds the program instructions and settings required to set up the computer and is not volatile and sustains the data even when the power is cut off.There are 4 main types of ROM

• ROM Chip (Firmware)
• PROM (Programmable Read Only Memory)
• EPROM (Erasable Programmable Read Only Memory)
• EEPROM (Eelctronically Erasable Programmable Read Only Memory)

RAM

ROM Chip

Number Systems

Decimal Number System

There are 10 digits i.e 1, 2, 3, 4, 5, 6, 7, 8, 9 available in decimal number system. It is known as Base 10 system. The value of a digit in a number depends upon its position in the number e.g. the number 546 in this system is represented as (546)10

546 = (4*102) + (8*101) + (6*100)

Binary Number System

The Binary Number System contains 2 unique digits 0 and 1. it is known as Base 2 system.

Octal Number System

There are 8 unique digits available in octal number system. These are 0, 1, 2, 3, 4, 5, 6, 7. thus, any number formed is the combination of these digits. It is known as Base 8 system.

Hexadecimal Number System

There are 16 unique digits available in Hexadecimal number system. These are 0, 1, 2, 3, 4, 5, 6, 7, 8, A, B, C, D, E, F where A denotes 10, B denotes 11………,F denotes 15. thus any number formed is a combination of these digits. It is known as Base 16 system.