basic concept of computer

Microsoft Office 2007 – Illustrated Introductory, Premium Video Edition

Understanding Essential Computer Concepts

2Microsoft Office 2007-Illustrated Introductory, Premium Video Edition

• Investigate types of computersInvestigate types of computers• Examine computer systemsExamine computer systems• Examine input devicesExamine input devices• Examine output devicesExamine output devices• Investigate data processingInvestigate data processing• Understand memoryUnderstand memory

ObjectivesObjectives


• Understand storage mediaUnderstand storage media• Explore data communicationsExplore data communications• Learn about networksLearn about networks• Learn about security threatsLearn about security threats• Understand system softwareUnderstand system software• Understand application softwareUnderstand application software

ObjectivesObjectives


Defining ComputersDefining Computers

A A computercomputer is an electronic device is an electronic device that:that:

• accepts inputaccepts input• processes dataprocesses data• stores datastores data• produces outputproduces output


Investigating Types of Investigating Types of ComputersComputersThe categories of computers are:The categories of computers are:• Personal computersPersonal computers

• DesktopDesktop• Notebook (Laptop) Notebook (Laptop) • Tablet PCTablet PC

• Hand-heldsHand-helds• PDAsPDAs• MP3 playersMP3 players• Cell phonesCell phones

• MainframesMainframes• SupercomputersSupercomputers


Investigating Types of Investigating Types of ComputersComputers

PersonalPersonal computerscomputers are used for general computing tasks. are used for general computing tasks.

Hand-heldHand-held computerscomputers fit in the palm of your hand and run fit in the palm of your hand and run on batteries.on batteries.

MainframesMainframes are used by companies to provide centralized are used by companies to provide centralized storage, processing, and management for large amounts of storage, processing, and management for large amounts of data.data.

SupercomputersSupercomputers are the largest and fastest of computers, are the largest and fastest of computers, and can process an enormous volume of data.and can process an enormous volume of data.


Investigating Types of ComputersInvestigating Types of Computers

• Notebook Notebook computercomputer• also referred to also referred to

as a laptop as a laptop computercomputer

• smallsmall• lightweightlightweight• portableportable


Investigating Types of ComputersInvestigating Types of Computers• PDAsPDAs

• Personal Digital Personal Digital AssistantsAssistants

• generally used to maintain an electronic appointment book, address book, calculator, and notepad


Investigating Types of ComputersInvestigating Types of Computers

SupercomputersSupercomputers are the largest and fastest of are the largest and fastest of computers, and can process an enormous computers, and can process an enormous volume of data.volume of data.


Understanding TerminalsUnderstanding Terminals• TerminalTerminal

• has a keyboard for inputhas a keyboard for input• monitor for outputmonitor for output• processes little or no data on its ownprocesses little or no data on its own

• Terminal emulatorTerminal emulator• personal computer, workstation, or serverpersonal computer, workstation, or server• uses special software to imitate a terminaluses special software to imitate a terminal• allows the PC to communicate with he allows the PC to communicate with he

mainframe or supercomputermainframe or supercomputer


Examining Computer SystemsExamining Computer Systems

A A computer systemcomputer system is made up of: is made up of:

• HardwareHardware—the physical components—the physical components

• SoftwareSoftware—the programs or lists of —the programs or lists of instructionsinstructions



• ArchitectureArchitecture or or configurationconfiguration is the is the design of the computer.design of the computer.• As in, what does the computer consist As in, what does the computer consist

of?of?

• SpecificationsSpecifications are the technical details are the technical details about each component.about each component.• As in, how big is the monitor?As in, how big is the monitor?



• Data • The words, numbers, figures,

sounds, and graphics that describe people, events, things, and ideas

• Processing• Modifying data



• MotherboardMotherboard• where processing

tasks occur • located inside the

computer • the main electronic

component of the computer

• contains the CPU



• The data you type into the computer is called The data you type into the computer is called inputinput..

• The result of the computer processing your The result of the computer processing your input is called input is called outputoutput..

• Peripheral devicesPeripheral devices accomplish the input, accomplish the input, output, and storage functions.output, and storage functions.


Examining Computer SystemsExamining Computer Systems• MicroprocessorMicroprocessor

• a silicon chip a silicon chip designed to designed to manipulate datamanipulate data

• its speed is its speed is determined by:determined by:

• Clock speedClock speed• Word sizeWord size• Processor typeProcessor type


Examining Input DevicesExamining Input Devices

Some input devices are:Some input devices are:

• KeyboardKeyboard• MouseMouse• TrackballTrackball• Touch padTouch pad• Pointing stickPointing stick• ScannerScanner• MicrophonesMicrophones

Cordless mouseCordless mouse


Using Assistive DevicesUsing Assistive Devices

• People who cannot use their arms or hands instead can use foot, head, or eye movements to control the pointer.

• People with poor vision can use keyboards with large keys for input, screen enlargers to enlarge the type and images on the monitor, or screen readers to read the content of the screen aloud.


Examining Output DevicesExamining Output Devices

• MonitorsMonitors and and printersprinters are common are common output devices.output devices.

• CRT monitorsCRT monitors and and flat panel monitorsflat panel monitors are two types of monitors.are two types of monitors.


Examining Output Examining Output DevicesDevices

Factors that influence Factors that influence a monitor’s quality a monitor’s quality

are:are:

• Screen SizeScreen Size• ResolutionResolution• Dot PitchDot Pitch


Examining Output DevicesExamining Output Devices

Types of printersTypes of printers• LaserLaser• Dot MatrixDot Matrix• InkjetInkjet

InkjetInkjet printerprinter


Investigating Data ProcessingInvestigating Data Processing

• A computer file is a named collection of stored data.

• An executable file contains the instructions that tell a computer how to perform a specific task; for instance, the files that are used while the computer starts are executable.

• A data file is created by a user, usually with software.



• Computers interpret every signal as Computers interpret every signal as “on” or “off.”“on” or “off.”

• 1 (“on”) and 0 (“off”) are referred to as 1 (“on”) and 0 (“off”) are referred to as bitsbits..

• Eight bits is a Eight bits is a bytebyte. Each byte . Each byte represents a unique character.represents a unique character.



• KilobyteKilobyte ( (KBKB) = one thousand ) = one thousand bytesbytes

• MegabyteMegabyte ( (MBMB) = one million bytes) = one million bytes• GigabyteGigabyte ( (GBGB) = one billion bytes) = one billion bytes• TerabyteTerabyte ( (TBTB) = one trillion bytes) = one trillion bytes


Investigating Data ProcessingInvestigating Data Processing• Each ASCII number

represents an English character

• Computers that run the Windows operating system use the set of Extended ASCII definitions defined by the American National Standards Institute (ANSI).

ANSI standard sample ASCII codeANSI standard sample ASCII code


Understanding MemoryUnderstanding Memory

• Computer Computer memorymemory is a set of storage is a set of storage locations on the motherboard.locations on the motherboard.

• There are five types of memory:There are five types of memory:• Random access memory (RAM)Random access memory (RAM)• Cache memoryCache memory• Virtual memoryVirtual memory• Read-only memoryRead-only memory• Complementary metal oxide Complementary metal oxide

semiconductor memory (CMOS)semiconductor memory (CMOS)



• RAMRAM • Temporary memory that is constantly Temporary memory that is constantly

changing while the computer is on.changing while the computer is on.• Also called Also called volatile memory volatile memory and and temporary temporary

memorymemory..• Cache memoryCache memory

• Special high-speed memory chip on the Special high-speed memory chip on the motherboard or CPU motherboard or CPU

• Stores frequently and recently accessed data Stores frequently and recently accessed data and commands.and commands.



• Virtual memoryVirtual memory is extra memory that is extra memory that simulates RAM if more is needed.simulates RAM if more is needed.

• Read-only memory (ROM)Read-only memory (ROM) is the permanent is the permanent storage location for a set of instructions the storage location for a set of instructions the computer uses.computer uses.

• CMOSCMOS memory is semi-permanent memory is semi-permanent information about where essential software is information about where essential software is stored.stored.


Understanding Storage MediaUnderstanding Storage Media

• Magnetic storage devices • Store data as magnetized

particles on mylar, which is then coated on both sides with a magnetic oxide coating


Understanding Storage MediaUnderstanding Storage Media• Common magnetic storage

devices • hard disks—several magnetic oxide

covered metal platters usually sealed in a case inside the computer

• tape—inexpensive, slow, archival storage for large companies who need to back up large quantities of data.

• floppy disks—flat circles of magnetic oxide-coated mylar enclosed in a hard plastic case; almost obsolete



• Optical storage devices• polycarbonate discs coated with a

reflective metal on which data is recorded using laser technology as a trail of tiny pits or dark spots in the surface of the disc

• the data that these pits or spots represent can then be “read” with a beam of laser light



• Types of optical storage devicesTypes of optical storage devices• CD—can store 700 MB of dataCD—can store 700 MB of data• DVD—can store between 4.7 and DVD—can store between 4.7 and

15.9 GB of data15.9 GB of data• Blu-ray discs and HD-DVD can store Blu-ray discs and HD-DVD can store

between 15 and 50 GB of databetween 15 and 50 GB of data



• Flash memory—similar to ROM except that it can be written to more than once.

• Flash memory cards• small, portable cards encased in hard

plastic to which data can be written and rewritten

• used in digital cameras, handheld computers, video game controllers, and other devices


Understanding Storage MediaUnderstanding Storage Media• USB flash storage

device (USB drive, flash drive)

• popular type of flash memory

• available in a wide range of sizes from 32 MB to 16 GB

• plug directly into the USB port of a personal computer

• are about the size of a pack of gum and often have a ring that you can attach to your key chain.


Erasing and Rewriting on Erasing and Rewriting on CDs and DVDsCDs and DVDs

• CD-ROMCD-ROMs are for “read-only” access.s are for “read-only” access.

• CD-RCD-R drives allow you to record data on a drives allow you to record data on a CD-R disk.CD-R disk.

• CD-RWCD-RW drives allow you to write data on a drives allow you to write data on a CD-RW disk and access and modify data.CD-RW disk and access and modify data.

• DVD-RDVD-R and and DVD+RDVD+R are recordable. are recordable.


Exploring Data CommunicationsExploring Data Communications

Data communicationsData communications is the transmission of text, is the transmission of text, numeric, voice, or video data from one computer to numeric, voice, or video data from one computer to another.another.

The four essential components of data communications The four essential components of data communications are:are:• SenderSender• ChannelChannel• ReceiverReceiver• ProtocolsProtocols



• A A sendersender is the computer that originates the is the computer that originates the message.message.

• The The messagemessage is sent over a channel, such as a is sent over a channel, such as a telephone.telephone.

• The The receiverreceiver is the computer at the message’s is the computer at the message’s destination.destination.

• ProtocolsProtocols are the rules that establish the are the rules that establish the transfer of data between sender and receiver.transfer of data between sender and receiver.


Exploring Data CommunicationsExploring Data Communications• Device driver (or simply driver)

• handles the transmission protocol between a computer and its peripheral devices

• a computer program that can establish communication because it contains information about the characteristics of your computer and of the device

• Data bus • the data path between the microprocessor,

RAM, and the peripherals along which communication travels



Components needed to connect a printer to a computerComponents needed to connect a printer to a computer



PCs have several types of ports:PCs have several types of ports:• ParallelParallel• SerialSerial• SCSISCSI• USBUSB• MIDIMIDI• EthernetEthernet



• Parallel port—Parallel port—transmits data eight bits at a transmits data eight bits at a timetime

• Serial portSerial port—transmits data one bit at a time—transmits data one bit at a time• SCSI SCSI (small computer system interface,

pronounced “scuzzy”) port—port—provides an provides an interface for one or more peripheral devices interface for one or more peripheral devices at the same portat the same port

• USB USB (Universal Serial Bus) port—port—a high-a high-speed serial port which allows multiple speed serial port which allows multiple connections at the same portconnections at the same port


Exploring Data CommunicationsExploring Data Communications• Sound card port—usually includes jacks Sound card port—usually includes jacks

for speakers and a microphone, which are for speakers and a microphone, which are designed to work with a designed to work with a MIDI MIDI ((Musical Musical Instrument Digital InterfaceInstrument Digital Interface, pronounced , pronounced “middy”) “middy”) cardcard

• Ethernet port—Ethernet port—used to connect to used to connect to another computer, a LAN, a modem, or another computer, a LAN, a modem, or sometimes directly to the Internet; allows sometimes directly to the Internet; allows data to be transmitted at high speeds.data to be transmitted at high speeds.


Exploring Data Exploring Data CommunicationsCommunications

Computer ports and connectionsComputer ports and connections

Power connection

Mouse port

FireWire port

Network port

Phone line connection

Speaker and microphone connections

USB ports

Monitor port

Audio connection

Keyboard port


Learning about NetworksLearning about Networks• NetworkNetwork

• connects one computer to other computers and connects one computer to other computers and peripheral devicesperipheral devices

• Network interface cardNetwork interface card ( (NICNIC) ) • creates a communications channel between the creates a communications channel between the

computer and the networkcomputer and the network• a cable connects the NIC port to the networka cable connects the NIC port to the network

• Network softwareNetwork software• establishes the communications protocols that will establishes the communications protocols that will

be observed on the networkbe observed on the network• controls the traffic flow of data traveling through controls the traffic flow of data traveling through

the networkthe network


Learning about NetworksLearning about Networks

• ServerServer• acts as the central storage location for programs • provides mass storage for most of the data used on the

network• ClientClient—computers on a network dependent on a —computers on a network dependent on a

serverserver• Client/server networkClient/server network—a network with server that —a network with server that

acts as the central storage locationacts as the central storage location• Peer-to-peer networkPeer-to-peer network

• a network without a server a network without a server • all of the computers are equalall of the computers are equal



• Standalone computerStandalone computer—a—a personal computer that is not connected to a network

• WorkstationWorkstation—a—a personal computer that is connected to a network

• NodeNode—any device connected to the —any device connected to the networknetwork



Network configurationNetwork configuration

Workstation

Workstation

Your local workstation

Server Printer


Learning about NetworksLearning about Networks• LANLAN ( (local area networklocal area network))

• computers and peripherals located close to each computers and peripherals located close to each otherother

• WAN WAN ((wide area networkwide area network))• more than one LAN connected together• the Internet is the largest example of a WAN

• WLAN WLAN ((wireless local area networkwireless local area network))• computers and peripherals that use high-

frequency radio waves instead of wires to communicate and connect in a network

• Wi-Fi (wireless fidelity) describes WLANs connected using a standard radio frequency established by the Institute of Electrical and Electronics Engineers (IEEE)


Learning about NetworksLearning about Networks• PAN PAN ((personal area networkpersonal area network)—)—a network that

allows two or more devices located close to each other to communicate or to connect a device to the Internet

• infrared technologyinfrared technology——uses infrared light waves to beam data from one device to another

• BluetoothBluetooth——uses short range radio waves to connect a device wirelessly to another device or to the Internet

• WiMAX WiMAX (Worldwide Interoperability for Microwave Access)

• allows computers to connect over many miles to a LAN• a WiMAX tower sends signals to a WiMAX receiver built or

plugged into a computer



Using modems to send and receive dataUsing modems to send and receive data

Sending site

Digital signal

Modem

Analog signal

Modem

Digital signal

Receiving site


Learning about Security ThreatsLearning about Security Threats

• Security • refers to the steps a computer

owner takes to prevent unauthorized use of or damage to the computer


Learning about Security ThreatsLearning about Security Threats• Malware

• describes any program that is intended to cause harm or convey information to others without the owner’s permission

• Viruses • harmful programs that instruct your computer

to perform destructive activities, such as erasing a disk drive

• Antivirus software (virus protection software) searches executable files for the sequences of characters that may cause harm and disinfects the files by erasing or disabling those commands


Learning about Security ThreatsLearning about Security Threats• Spyware

• programs contained with other programs that track a computer user’s Internet usage and send this data back to the company or person that created it

• usually installed without the computer user’s permission or knowledge

• Anti-spyware software detects spyware and deletes them

• Adware • software installed with another program usually with the

user’s permission• generates advertising revenue for the program’s creator

by displaying targeted ads to the program’s user


Learning about Security ThreatsLearning about Security Threats• Firewall

• prevents other computers on the Internet from accessing a computer and prevents programs on a computer from accessing the Internet without the computer user’s permission

• can be either hardware or software• router

• a device that controls traffic between network components

• usually has a built-in firewall.

• software firewalls track all incoming and outgoing traffic


Learning about Security ThreatsLearning about Security Threats• Spoofed site

• a Web site set up to look like another Web site, but which does not belong to the organization portrayed in the site

• the URL (address on the Web) looks similar to a URL from the legitimate site

• usually set up to try to convince customers of the real site to enter personal information

• Phishing • the practice of sending e-mails to customers or potential

customers of a legitimate Web site asking them to click a link in the e-mail

• the link leads to a spoofed site• Pharming

• when a criminal breaks into a DNS server (a computer responsible for directing Internet traffic) and redirect any attempts to access a particular Web site to the criminal’s spoofed site


Protecting Information with Protecting Information with PasswordsPasswords• Logging inLogging in

• signing in with a user name and signing in with a user name and passwordpassword

• Strong passwordStrong password• at least eight charactersat least eight characters• consists of upper- and lowercase letters consists of upper- and lowercase letters

and numbersand numbers• does not include common personal does not include common personal

informationinformation

basic concept of computer

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