CCC Flash card for Practice Exam

Computer

Computer is an advanced electronic device that takes raw data as input from the user and processes it under the control of set of instructions (called program), gives the result (output), and saves it for the future use.

Functionalities of a computer

Takes data as input. Stores the data/instructions in its memory and use them when require Processes the data and converts it into useful information. Generates the output

Characteristics of Computer

1) Automatic 2) High Speed 3) Accuracy 4) Storage Capability 5) Diligence 6) Versatility 7) Reliability 8) Reduction in Paper Work

Application of Computer

Analog Computer

An analog computer (spelt analogue in British English) is a form of computer that uses continuous physical phenomena such as electrical, mechanical, or hydraulic quantities to model the problem being solved. 

Digital Computer

A computer that performs calculations and logical operations with quantities represented as digits, usually in the binary number system.

Hybrid Computer

A combination of computers those are capable of inputting and outputting in both digital and analog signals. A hybrid computer system setup offers a cost effective method of performing complex simulations.

Keyboard

Keyboard is the most common and very popular input device which helps in inputting data to the computer Keyboards are of two sizes 84 keys or 101/102 keys, but now keyboards with 104 keys or 108 keys are also available for Windows and Internet.

Mouse

Mouse is most popular pointing device to make selection on screen.

Joystick

Joystick is also a pointing device which is used to move cursor position on a monitor screen. The function of joystick is similar to that of a mouse. It is mainly used in Computer Aided Designing(CAD) and playing computer games.

Light Pen

Light pen is a pointing device which is similar to a pen. It is used to select a displayed menu item or draw pictures on the monitor screen.

Track Ball

Track ball is an input device that is mostly used in notebook or laptop computer, instead of a mouse.

Scanner

Scanner is an input device which works more like a photocopy machine. It is used when some information is available on a paper and it is to be transferred to the hard disc of the computer for further manipulation

Digitizer

Digitizer is an input device which converts analog information into digital form. Digitizer can convert a signal from the television or camera into a series of numbers that could be stored in a computer.

Microphone

Microphone is an input device to input sound that is then stored in digital form. The microphone is used for various applications like adding sound to a multimedia presentation or for mixing music.

Optical Character Reader(OCR)

OCR is an input device used to read a printed text. OCR scans text optically character by character, converts them into a machine readable code and stores the text on the system memory.

Bar Code Readers

Bar Code Reader is a device used for reading bar coded data (data in form of light and dark lines). Bar coded data is generally used in labelling goods, numbering the books etc.

Optical Mark Reader(OMR)

OMR is a special type of optical scanner used to recognize the type of mark made by pen or pencil. It is used where one out of a few alternatives is to be selected and marked.

Monitors

Monitors, commonly called as Visual Display Unit (VDU), are the main output device of a computer.

Cathode Ray Tube (CRT)

CRT or Cathode Ray Tube Monitor is the typical monitor that you see on a desktop computer. It looks a lot like a television screen, and works the same way. This type uses a large vacuum tube.

Liquid Crystal Displays (LCD)

This type of monitors are also known as flat panel monitor. Most of these employ liquid crystal displays (LCDs) to render images. These days LCD monitor are very popular.

Printers

Printer is an output device, which is used to print information on paper There are two types of printers a) Impact Printers b) Non-Impact Printers

Impact Printers

The impact printers print the characters by striking them on the ribbon which is then pressed on the paper.

Characteristics of Impact Printer

Very low consumable costs Very noisy Useful for bulk printing due to low cost There is physical contact with the paper to produce an image

Non-impact Printers

Non-impact printers print the characters without using ribbon. These printers print a complete page at a time so they are also called as Page Printers.

Plotter

A plotter is a special kind of output device that, like a printer, produces images on paper, but does so in a different way. Plotters are designed to produce large drawings or images.

Speaker

Speakers are another type of output device, which allow you to listen to voice like music, and conversation with people.

Projector

A projector is a device that uses light and lenses to take an image and project a magnified image onto a larger screen or wall.

Central Processing Unit - CPU

CPU is considered as the brain of the computer. CPU performs all types of data processing operations. It stores data, intermediate results and instructions(program). It controls the operation of all parts of computer.

Cache Memory

Cache memory is a very high speed semiconductor memory which can speed up CPU. It acts as a buffer between the CPU and main memory. It is used to hold those parts of data and program which are most frequently used by CPU

Random Access Memory

RAM(Random Access Memory) is the internal memory of the CPU for storing data, program and program result. It is read/write memory which stores data until the machine is working.

Read Only Memory

ROM stands for Read Only Memory. The memory from which we can only read but cannot write on it. This type of memory is non-volatile. The information is stored permanently in such memories during manufacture

Types of ROM

PROM (Programmable Read only Memory) EPROM(Erasable and Programmable Read Only Memory) EEPROM(Electrically Erasable and Programmable Read Only Memory)

Machine Languages

Machine language is the only language that a computer understands. Machine language is a low-level programming language.

Number system

A numeral system is a writing system for expressing numbers; that is, a mathematical notation for representing numbers of a given set, using digits or other symbols in a consistent manner. 

Binary number system

Hexadecimal number system

Octal number system

The number system with base or radix digit (8) is known as an octal number system.This system consists of eight digits, i.e. 0,1,2,3,4,5,6 and 7.

Data Processing

Data processing is the process in which the information is gathered/collected and stored in the form of electronic media and manipulated into a more useful form.

Multimedia

A media which combines different content forms of text, audio, video, animation, interactive features, still images to get a finished product is defined as multimedia.

Graphical User Interfaces (GUI)

graphical user interface (GUI /ˈɡuːi/) is a form of user interface that allows users to interact with electronic devices through graphical icons and visual indicators such as secondary notation, instead of text-based user interfaces.

Taskbar

A taskbar is an element of a graphical user interface which has various purposes. It typically shows which programs are currently running.

Menu Bar

The Menu bar is a part of a screen or a window where drop down menus are displayed.

RTF

Rich Text Format is a document format that is readable by most word processors.The RTF file is a plain text file representation of a formatted document.

PDF

Portable Document Format is a file format that preserves all of the fonts, formatting, colors, and graphics of a document.

Introduction to Computer

The term Computer is derived from the Latin word Computare which means to compute or to calculate.

Classification of Computer

Analog Computer Hybrid Computer Digital Computer

Micro Computer

Micro Computer is a small, relatively inexpensive computer with a microprocessor as its CPU. The invention of the microprocessor (single chip CPU) gave birth to the much cheaper microcomputers

Mini Computer

Mini computers were designed for control, instrumentation, human interaction, and communication switching as it is distinct from calculation and record keeping.

Mainframe Computers

Mainframe Computers is a powerful multi-user computer that can support thousand users simultaneously. Mainframe computers can also process data at very high speeds, i.e., hundreds of million instructions per second and they are also quite expensive

Super Computer

Super Computers are best in terms of processing capacity and also the most expensive one. An extremely fast computer that can perform hundreds of millions instructions per second.

Components of Computer System

The computer is an electronic device that accepts (reads) data from the user and processes the data by performing calculations and operations on it, and generates (writes) the desired output. A computer consists of four major components such as  Input Devices (Input Unit)  CPU (Processing Unit)  Memory (Storage Unit)  Output Devices (Output Unit)

Input Unit

An input device is a hardware or peripheral device used to send data to a computer. An input device allows users to communicate and feed instructions and data to computers for processing, display, storage and/or transmission.

CPU (Processing Unit)

The CPU is the heart of the computer, it is the part of a computer which interprets and executes instruction.

Decimal Number System

The number system that we use in our day-to-day life is the decimal number system. The decimal number system has a base 10 as it uses 10 digits from 0 to 9.

ASCII Code

ASCII stands for American Standard Code for Information Interchange.  ASCII character encoding provides a standard way to represent characters using numeric codes.

Unicode

Unicode is a universal character encoding standard. It defines the way individual characters are represented in text files, web pages and other types of documents

What is CPU?

CPU stands for Central Processing Unit. The Central Processing Unit (CPU) is the brain of the computer, it is a part of computer which interprets and executes instruction.

Arithmetic and Logical Unit

The Arithmetic and Logic Unit performs arithmetic and logical operations. Arithmetic operations include addition, subtraction, multiplication and division.

Logic Unit

Logic Unit performs following operations such as AND, OR, NOT, XOR, NOR, NAND, etc

Control Unit

A Control Unit (CU) handles all processor control signals. It generates timing signals such that the coordination among devices take place

Booting

Booting is the initialization of the computerized system. The booting process can be hard when electrical power to the CPU is switched from off to on.

Primary memory

Primary Memory is used for immediate access of data by the processor. Most computer systems around the world use primary memory. Primary memory can be divided into two types.  RAM (Random Access Memory)  ROM (Read Only Memory)

RAM (Random Access Memory)

Random Access Memory is the central storage unit in a computer system. The information stored in the RAM is typically loaded from the computers hard disk, and includes data related to the operating system and certain applications.

Static RAM (SRAM)

In SRAM, a bit of data is stored using the state of a flip-flop. This is most expensive among other forms of RAMs, but is generally faster and requires less power than DRAM and, in modern computers, is often used as cache memory for the CPU.

Dynamic RAM (DRAM)

Widely used in modern computers as primary memory, DRAM is slower than SRAM, but is inexpensive due to its one transistor-one capacitor paired assembly of memory storage.

PROM (Programmable Read-Only Memory)

PROM is a type of ROM that is programmed after the memory is constructed. While PROM cannot be erased, two other versions of PROM have been developed that can be erased and reprogrammed.

EPROM (Electrically Erasable Programmable Read-Only Memory)

EEPROM can be erased with an electrical charge and is used in flash memory.

Secondary Memory (Secondary Storage Device)

Secondary Memory refers to storage devices, such as hard drives and Solid State Drives (SSD).It may also refer to removable storage media, such as USB flash drives, CDs, and DVDs.

Floppy disk

These are small removable disks that are plastic coated with magnetic recording material. This portable storage device is a rewritable media and can be reused a number of times.

Hard disk drive

Another form of auxiliary storage is a hard disk. A hard disk consists of one or more rigid metal plates coated with a metal oxide material that allows data to be magnetically recorded on the surface of the platters.

Optical disk

An Optical disk is any storage media that hold content in digital format and is read using a laser assembly is considered as optical media.

Function keys

Keys that act as shortcuts for performing certain functions such as saving files or printing data. Function keys usually are lined along the top of the keyboard labeled F1 through F12.

Web Cam

A webcam is a video camera that feeds its image to the computer. When the image is captured by the computer, the video stream may be saved or viewed or sent to other network via system such as the internet and email as an attachment.

Printers

A printer is an electromechanical device which converts the text and graphical documents from electronic form to the physical form and it used to print information on paper.

Types of printer

There are different types of printers and most commonly used printers are  Dot matrix printer  Inkjet printer  Laser printer

Dot matrix printer

Dot Matrix Printer is a popular computer printer that prints text and graphics on the paper by using tiny dots to form the desired shapes.

Inkjet printer

Inkjet printing is a type of computer printer that creates a digital image by propelling droplets of ink onto paper, plastic, or other substrates.

Laser printer

Laser printing is an electrostatic digital printing process that rapidly produces high quality text and graphics by passing a laser beam over a charged drum to define a deferentially charged image.