2What is a computer?A computer is a device for processing data. More precisely a computer is a device that accepts input, processes data, stores data, and produces output, all according to a series of stored instructions.A program is a set of instructions to perform a task.
3A Computer is a device that accepts inputprocesses datastores dataproduces output(all according to a series of stored instructions)
6Computer system consists of: Hardware includes the electronic and mechanical devices that process data. Examples: microprocessor, key board.Peripheral devices expand the computer’s input, output, and storage capabilities.Examples: Printers.Software: programs
7Computer NetworkA computer network consists of two or more computers and other devices that are connected for the purpose of sharing data and programs.
8LANA LAN (local Area network) is a computer network that is located within a limited geographical area, such as a building or campus.
9COMPUTER FUNCTIONSComputer Input is whatever is put into a computer system.Input can be supplied by a person, by the environment, or by another computer.Data refers to the symbols that represent facts, objects, and ideas.
10COMPUTER FUNCTIONSComputer manipulate data in many ways, and we call this manipulation processing
11COMPUTER FUNCTIONSThe instructions that tell a computer how to carry out the processing tasks are referred to as a computer program.In a computer most processing takes place in the central processing unit (CPU) (also known as microprocessor)A computer stores data so that it will be available for processing.Memory is an area of a computer that temporarily holds data waiting to be processed, stored, or output.Storage is the area of a computer that holds data on a permanent basis when it is not immediately needed for processing.
12Computer FunctionsWords, symbols, numbers, sound, pictures, program instructionsInputProgram calculates, sorts modifies dataUses microprocessor or CPUProcessResults of processingReports, graphs, documents, picturesPrinter or monitorOutputMemory is temporary holding area (RAM)Storage is permanent (disk)Store
14Less Powerful Computers PC/microcomputerWorkstationsHandheld computer/PDACD: video on PDAVideogame consoleSony PlayStation®
15Personal ComputerA PC is designed to meet the computing needs of a person. It typically provides access to a wide variety of computing applications, such word processing, photo editing, , etc.There are four types: desktop, notebook computers, workstations, and video game console.Workstations are usually powerful desktop computers for special purposes.
16ServersThe purpose of a server is to serve the computers on a network by supplying them with data.A PC, workstation, mainframe or supercomputer can work as a server.
17MainframesA mainframe is a large and expensive computer capable of simultaneously processing data for hundreds or thousands of users.Mainframes are used by businesses, universities, or governments to provide centralize storage, processing and management of large amount of data.
18SupercomputersA computer is a supercomputer if, at the time of construction, it is one of the fastest computers in the world.Supercomputers are used in complex tasks such as breaking codes or climate modeling.The CPU of a supercomputer contains thousands of microprocessors.
20System UnitThe system unit is the case that holds the power supply, storage devices, and the circuit boards, including the main circuit board (also called the “mother board”), which contains the microprocessor.
23NotesYou can use a modem to establish an Internet connection using an standard telephone line.Computers have many types of storage devices that are used to store data when the power is turned off.
24Storage Devices Floppy disk drive Hard disk drive CD-ROM drive DVD driveCD writer
25Storage DevicesA floppy disk drive is a storage device that reads data from and writes data to a floppy disks.A hard disk drive can store billions of characters of data.A CD-ROM drive is a storage device that uses that uses laser technology to read data that is permanently stored on data or audio CDs.A DVD drive can read data from CDs DVDs, or DVD movie discs.
26Data vs. Information Data (symbols) used by computers Information (meaningful) used by people
27DataComputers process and store data using the binary number system and several other codes designed expressly for electronic data.Binary number system has only two digits 0 and 1.Each 0 and 1 is a Bit.Byte (8 bits)
28Files Collection of data on a storage medium Data file (passive) Executable file (active)Filename and extensionImage.jpgWord.exeResume.doc
29SoftwareApplication Software is a set of computer programs that helps a person carry out a task.System Software is a set of computer programs that helps a computer carry out basic tasks.
30System SoftwareHelps the computer monitor itself in order to function efficientlyOperating systemMaster controller of all computer activitiesPopular operating systemsPCs: Microsoft Windows, Mac OSHandhelds: Windows CE and Palm OSServers: Linux and UNIXCD video: windows interface
31Computers that operate in essentially the same way are said to be compatible. Two of the most important factors that influence the compatibility of two computers are the microprocessor and the operating system.A platform consists of the underlying hardware and software of the computer system.
32Platform Mac and PC compatibility is an issue Microprocessor + Operating systemMac and PC compatibility is an issueApple computer = Mac platformOriginal IBM computer = Windows or PC platformInfo web: Apple computers
33Designed to carry out a particular task Application SoftwareMicrosoft ExcelMicrosoft PowerPointDesigned to carry out a particular task
34Internet Basics (Cyberspace) Internet is a collection of local, regional, national and international computer networks that are linked together to exchange data and distribute processing tasks.Infoweb: cyberspaceInfoweb: internet resources
35Internet TerminologyThe Internet backbone defines main Internet routesroute= telecommunication linkConstructed and maintained by major telecommunications companies.TCP/IP is a standard set of rules for electronically addressing and transmitting data.Transmission Control Protocol/ Internet Protocol
37Internet TerminologyIP Address: unique number for each Internet computerPackets: small chunks of data ready to travel the InternetRouter: helps send along the packets to correct destinationCD screentour: web sites provides files
38Internet Resources Internet Telephony Usenet E-commerce Instant MessagingWeb SitesInternet RadioDownload Or UploadChat Groups
39Modem Internet Connections Dial-up connection via modem requires a modem, which converts your computer’s digital signals into a type of signal that can travel over phone lines.The maximum speed is 56Kbps, or 56,000 bits per second., E-commerce, and chat.Infoweb: national ISPsLab: making a dialup connectionCD video: computer modems
40Faster Internet Connections ISDN (Integrated Services Digital Network) provides data transfer speeds of either 64K or 128K.Always-on and expensiveDSL (Digital Subscriber Line) is a generic name for a family of high –speed Internet links, including ADSL, SDSL, and DSL lite.Up to 125 times faster than dialupBoth ISDN and DSL connections require proximity to a telephone switching station.
41Internet Service Provider (ISP) An ISP is a company that maintains Internet computers and telecommunications equipment in order to provide Internet access to businesses, organizations and individualsUser ID and password requiredaccount monthly feeShould have local access telephone numbers
42World Wide Web BasicsThe web (or World Wide Web) is a collection of files that are interconnected through of hypertext.Hypertext: text, video, pictures.A Web pages is a collection of hypertext documents and links (or hyperlinks).A link is a related document.A web site is a collection of web pages with an Internet address.A Web server is a computer that stores and distributes web pages.Infoweb: hypertext
43World Wide Web Basics http://www.cnn.com/showbiz/movies.htm URL (uniform resource locator) is the internet address of a web site.HTTP ( Hypertext Transfer Protocol) is the communications standard that is used to transport web documents over the Internet.HTML (Hypertext Markup Language) is a language to create web pages..htm or .html file extensionDocument nameand filenameextensionFoldernameWebserverprotocolstandard
44Browsers and Search Engines A browser is a software program that runs on your computer and helps you access web page.A search engine refers to a web site that provides a variety of tools to help you find information on the Web.Infoweb: browserLab: browsing and searchingMicrosoft Internet Explorer® and Netscape Navigator®