Presentation on theme: "What is a Computer? A computer is an electronic device operating under the control of instructions stored in its own memory unit, that can accept data."— Presentation transcript:
1 What is a Computer?A computer is an electronic device operating under the control of instructions stored in its own memory unit, that can accept data (input) process the data and generate results (output) and store the results for future use.
2 Hardware & Peripheral devices The electric, electronic, and mechanical equipment that makes up a personal computer is called hardware.Devices that surround the system unit (i.e., the keyboard, mouse, speakers, monitor, and so on) sometimes are known as peripheral devices.other devices (such as a scanner) that could be part of a computer system.
3 Information Processing Cycle Four general operations of computerInputProcessOutputStorage
4 Data Vs InformationData is a collection of raw facts, figures, and symbols, such as numbers, words, images, video and soundsData is given to computer during the input operationComputers manipulate the data and produce organized, meaningful and useful information
5 Processing speedToday’s supercomputer can perform 1.8 trillion operations per second.If a person did one arithmetic operation a second without stopping, it would take more than 31,000 years to perform the number of operations a supercomputer can do in one second.
6 Computer users, end users or just users People who use the computer directly or use the information it generates are called computer users, end users, or sometimes, just users.
7 Why is a computer so Powerful? The power of a computer comes from its ability to perform the information processing cycle quickly, reliably (low failure rate), and accurately.capacity to store large amounts of informationability to communicate with other computers
8 Computer Program or Software A detailed set of instructions that tells computer exactly what to do to perform an operations are called a computer program or software.What is the difference between hardware and software?
9 Hardware Vs SoftwareA 3.5 inch floppy disk is a hardware but the program that is stored in a floppy disk is a softwareComputer programs are written using programming languages (such as BASIC, COBOL, C, Pascal, and so on) each of which has specific rules, or syntax, governing its use.
10 Components of a computer Six primary components of the computer areInput devicesProcessor (control unit and arithmetic/logic unit)MemoryOutput devicesStorage devicesCommunication devicesThe processor, memory, and storage devices are inside the system unit.
11 Input DevicesAn input device is an hardware component that allows you to enter data, programs, commands and so on in to a computerDifferent types of input devices are designed to transmit different types of data or to transmit data in different ways.The two primary input devices used are the keyboard and the mouse
12 KeyboardKeyboard contains keys you press to enter data into the computerA desktop computer keyboard typically has 101 to 105 keys
13 MouseThe mouse is called a pointing device because it controls the movement of a pointer, or mouse pointer, on the computer screen and make selections from the screen.The mouse either use optical sensor or ball that detects the movement of the mouse
14 Processor Also called Central Processing Unit It has two units: Control Unit and Arithmetic logic unit.The control unit interprets the instructionsThe arithmetic logic unit (ALU) performs logical and arithmetic operations.Example: Celeron, Athlon XP, Pentium processors
15 Memory Also known as RAM (Random Access Memory) It stores InstructionsDataResults (information)Amount of memory in computers typically is measured in kilobytes or megabytes
16 Output Devices Display the processed information Example: Printer, Display deviceTwo types of printerImpactNonimpact
17 Impact and non impact printer Impact printer prints by striking an inked ribbon against the paperDot matrix printerNon impact printers form characters by means other than striking a ribbon against paperLaser printersInk-jet printers
18 Advantages of Non impact printers It can print higher quality text and graphics than an impact printerIt also do better job printing different fonts
19 Display DevicesA monitor is a display device that display the processed output.Two basic types of monitorCRT (cathode ray tube)LCD (liquid crystal display)CRT is the most common display device used with desktop computersLCD also called flat panel monitor uses a liquid display crystal, similar to digital watch, to produce images on the screenMonitor is composed of individual picture elements called pixels
20 Byte or Memory location 1 byte = 8 bits1KB = about 1,000 bytes, (1024 or 2^10)1MB = about 1,000,000 (one million) bytes, (1,048,576 or 2^20)1GB= about 1,000,000,000 (one billion) bytes (1,073,741,824 or 2^30)
21 Storage DevicesStorage devices are used to store instructions, data, and information when they are not being used in memorySix common types of storage devices arefloppy diskszip diskshard diskoptical discstapeMiniature storage media
22 Floppy Disks Floppy disk is a portable storage medium It consists of a thin, circular, flexible plastic disk with a magnetic coating enclosed in a square-shaped plastic shellA floppy disk drive is a device that can read from and write to a floppy diskFormatting is the process of preparing a disk for reading and writing by organizing the disk into storage locations called track and sectors
23 Zip Disks Portable magnetic media Hold about 500 times more than a standard floppy diskUsed to back up important data and information
24 Hard DiskA hard disk consists of one or more rigid metal platters coated with a metal oxide material that allows data to be recorded magneticallypersonal computer hard disks usually are fixed (i.e., not removable),some portable computers have removable hard disk drives
25 Optical disc Uses laser technology for recording Two types of optical discs are CD (compact disc) and DVD (digital video disc)CDs are available in a variety of formatsCD-ROMCD-RCD-RW
26 Optical disc DVDs are available in the following formats DVD-ROM DVD-RW
27 TAPECapable of storing large amounts of data and information at a low costPrimarily used for long-term storage and backup
28 Miniature Storage Media Rewritable media usually in the form of a flash memory cardIt is the primary storage media used with digital cameras, music players, PDAs and so on
29 Communication Devices Helps a computer to send and receive data, instructions, and information to and from one or more computersCommunication occur over transmission media, such as cables, telephone lines, satellites
30 Computer software Can be categorized in to two types System softwareApplication softwareSystem software is a program that controls the operations of computer equipmentOperating system is a part of system softwareApplication software consists of program that tell a computer how to produce informationExample: Word Processing, Spredsheet, database, presentation graphics
31 NetworksA network is a collection of computers and devices connected through the communication media such as cables, telephone lines, modems or other meansLocal area networkWide area network
32 Internet & Intranets Worlds largest network Links millions of computers by means of cables, telephone lines and other communication devicesUsers connect to the Internet either through an internet service provider or through an online service providerIntranet is a special type of web that is available only to the users of a particular type of computer network, such as a network used within a company or organization for internal communication.
33 World Wide Web Contains billions of document called web pages Web site is a collection of web pagesWeb browser helps to access and view web pagesEach web page has a unique address called URL (Uniform Resource Locator)URL consists of a protocol, domain name, and sometimes the path to a specific web page.Web server is a computer that delivers requested web pages
34 World Wide WebThe first web page in the web site is called the home pageA hyperlink is colored or underlined text or a graphic that, when clicked, connects to another web pageMicrosoft Internet Explorer is a widely used browser
35 Electronic Commerce Conducting business activities online Three types of e- commerceBusiness to Consumer (B2C) Business selling goods/products to the general publicConsumer to Consumer (C2C) Consumer selling directly to another consumerBusiness to Business (B2B) Business provides goods and services to other businesses
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