Computers Are Your Future © 2006 Prentice-Hall, Inc.

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 2 Computers Are Your Future Chapter 8 Networks: Communicating and Sharing Resources

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 3 What You Will Learn About Basic networking concepts Advantages and disadvantages of networks Peer-to-peer and client/server LANs Importance of network protocols Most widely used LAN protocol Special components of a WAN The difference between circuit-switching and packet switching networks

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 4 Network Fundamentals A computer network consists of two or more computers linked together to exchange data and share resources  LAN – local area network (small geographic area)‏  WAN – wide area network (large geographic area)

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 5 Communication Devices Convert data into signals Transform data from analog into digital signals and back Computers, modems, routers, switches, wireless access points, network interface cards modems routers switches Network Interface Cards computers

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 6 Communication Devices Workstations – computer connected to a network  Called clients  Contains a network interface card (NIC)‏

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 7 Communication Devices Routers – connect two or more LANs or WANs  Can determine the best path to route data  LANs often use switches which are similar to routers

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 8 Communication Devices File server  High capacity, high speed computer  Large hard drive  Contains a network operating system (NOS)‏

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 9 Network Fundamentals Network administrators  Install  Maintain  Support  Interact with users  Troubleshoot problems

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 10 Advantages of Networks Reduced hardware costs Application sharing Sharing information resources Centralized data management Connecting people

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 11 Disadvantages of Networks Loss of autonomy Lack of privacy Security threats Loss of productivity

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 12 Local Area Networks (LANs)‏ Network access is controlled by a network administrator Users can access software, data, and peripherals LANs require special hardware and software Computers connected to a LAN are called workstations or nodes Types of LANs:  Peer-to-peer  Client-server

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 13 LAN Hardware and Software Networking Hardware Network interface card (NIC) – Provides the connection between the computer and the network Inserted into a computer’s expansion slot Networking Software Operating system that supports networking (Unix, Linux, Windows, Mac OS)‏ Additional system software NIC

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 14 Peer-to-Peer Networks All computers on the network are treated as equal There are no file servers Users decide which files and peripherals to share Peer-to peer is not suited for networks with many computers Peer-to-peer is easy to set up; example: home networks

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 15 Client-Server Networks Typical corporate networks are client-server Client-server requires various topologies or physical layouts The network requires file servers, networked computers (clients), and a network operating system (NOS)‏ Clients send requests to servers for programs and data, and to access peripherals

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 16 LAN Topologies The physical layout of a LAN is called its topology Topologies resolve the problem of contention, which occurs when multiple users try to access the LAN at the same time  Collisions or corrupt data occur when different computers use the network at the same time Click to see examples Bus topology Called a daisy chain Every workstation is connected to a single cable Resolves collisions through contention management Difficult to add workstations Star topology Contains a hub or central wiring concentrator Easy to add workstations Resolves collisions through contention management Ring topology All workstations are attached in a circular arrangement A special unit of data called a token travels around the ring Workstations can only transmit data when they possess a token

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 17 Protocols Protocols are fixed, formalized standards that specify how computers can communicate over a network Protocol suite – The total package of protocols that specify how a network functions

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 18 Modulation Protocols Modulation protocols are communications standards that modems conform to Data transfer rate is the rate at which two modems can exchange data. It is measured in bits per second (bps)‏ A modulation protocol called V.90 enables modems to transfer data at 56 Kbps

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 19 Network Layers Network architecture is the overall design of a network The network design is divided into layers, each of which has a function separate from that of the other layers Protocol stack – The vertical (top to bottom) arrangement of the layers; each layer is governed by its own set of protocols user physical media user physical media receiving sending protocol layer stack

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 20 LAN technologies Ethernet – standard for large and small business LocalTalk – simplest LAN technology IBM Token Ring Network

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 21 Wi-Fi Wireless-fidelity Wireless LAN Use central server or access point Advantages  Fast (11 Mbps)‏  Reliable  Long range  Integrates with existing networks

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 22 Wide Area Networks (WANs)‏ WANs are similar to long-distance telephone systems  They have a local access number called a point of presence (POP)‏  They contain long-distance trunk lines called backbones

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 23 Backbones Backbones, high-capacity transmission lines, can be regional, continental, or transcontinental Internet backbones can carry 2.5 gigabits of data per second

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 24 WAN Protocols X.25 is the oldest packet switching protocol; it is used by automated teller machines and credit card authorization devices New protocols designed for digital lines and faster data transfer rates are:  Switched Multimegabit Data Service (SMDS)‏  Asynchronous Transfer Mode (ATM)‏

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 25 Circuit switching Networks create an end- to-end circuit between the sending and receiving computers Electronic switches establish and maintain the connection Switching and Routing Techniques Packet switching Outgoing messages are divided into fixed-size data units called packets Packets are numbered and addressed to the receiving computer Routers examine the packets and send them to their destination

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 26 Packet switching Circuit switching Delays in receiving packets Not ideal for real-time voice communication Efficient, less expensive, and reliable Will function if part of the network is down Costly A direct electrical connection between the computers is required Voice and real-time transmission No delivery delays DisadvantagesAdvantages Advantages and Disadvantages of Circuit and Packet Switching

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 27 WAN Applications LAN-to-LAN WANs are used to connect LANs at two or more geographic locations Companies use WANs to connect their branches to one network system Transaction Acquisition Information about transactions is instantly relayed to the corporate headquarters Point-of-sale (POS) terminals relay transactions to central computers through WANs

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 28 Chapter 8 Summary Computer networks link two or more computers to exchange data and share resources Two types of computer networks: Local area network (LAN)‏ Wide area network (WAN)‏ Computer networks: Reduce hardware costs Enable users to share applications Provide a means to pool an organization’s data Foster teamwork Peer-to-peer uses no file server

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 29 Chapter 8 Summary continued Network topologies are the physical layout of a LAN LAN topologies include: Bus topology Star topology Ring topology Protocols define how devices communicate with each other Ethernet is the most widely used LAN protocol

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 30 Chapter 8 Summary continued Point of presence (POP) is a WAN connection point Circuit switching creates permanent end-to- end circuit that is optimal for voice and real- time data Packet switching does not require a permanent switched circuit

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 31 Computers Are Your Future Chapter 5 Application Software: Tools for Productivity

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 32 You Will Learn... How system software supports application software The most popular types of horizontal applications The advantages and disadvantages of standalone programs, integrated programs, and suites The advantages of Web technology and file compatibility The concept of software versions and upgrades The differences between types of software The essential concepts and skills of using application software

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 33 Application Software Application software refers to programs that enable the user to be productive when using the computer

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 34 Personal Productivity Word Processing Spreadsheets Address Books Multimedia/Graphics Desktop Publishing Photo Editing 3D Rendering Internet Web Browsers Home/Education Personal Finance Tax Preparation Reference Games General-Purpose Applications General Purpose applications are applications used by many people to accomplish frequently performed tasks

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 35 Personal Productivity Database Spreadsheet Word Processor

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 36 Multimedia/Graphics Photo Editing 3D Rendering Desktop Publishing

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 37 Multimedia/Graphics Compression – reducing the file size of multimedia software  Lossless – file will be restored with no flaws  Lossy – eliminates information that is not perceived Decompression – restoring the file to full size

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 38 Paint Programs Paint programs can save your files as:  Graphics Interchange Format (GIF) – lossless, simple images, solid color  Joint Photographic Experts Group (JPEG) – lossy, photographs  Portable Network Graphics (PNG) – lossless  Windows Bitmap (BMP) – optional compression

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 39 Drawing programs – create vector (mathematically generated) graphics 3D Rendering Programs – add three-dimensional effects to graphic objects Image Editors – used to edit and transform bit- mapped images Animation – simulate motion Multimedia/Graphics

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 40 Audio – capture and process sound Video editors – modify digitized video Multimedia Authoring Systems – used to create multimedia presentations Multimedia/Graphics

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 41 Internet Web Browser

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 42 Home/Education Personal Finance Tax Preparation Reference Games

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 43 Home/Education Games are a $6 billion industry  MUDs (multiuser dungeons) – roll playing games  gMUDs (graphical MUDs) – 3D graphic environments

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 44 Tailor-made Applications Tailor-made applications are used for specialized fields Types of tailor-made applications:  Billing programs  Inventory tracking programs  Point of Sale software  Custom software

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 45 Integrated Programs and Suites: The All-in-One Approach Standalone programs are fully self-contained  Examples:  Microsoft Word  Microsoft Excel Integrated programs contain modules that share the same interface  Example:  Microsoft Works

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 46 Integrated Programs and Suites: The All-in-One Approach Software suites contain standalone programs that share resources with each other  Examples:  Microsoft Office  Corel WordPerfect Office  Lotus Smart Suite

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 47 Software Suite Individual applications share a common program code Popular office suites offer a word processor, spreadsheet, database, presentation, and other programs

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 48 Software Suites Lotus OrganizerCorel CentralMicrosoft OutlookPersonal information managers Freelance GraphicsCorel PresentationsMicrosoft PowerPointPresentation Graphics Lotus ApproachParadoxMicrosoft AccessDatabase Lotus 1-2-3Quattro ProMicrosoft ExcelSpreadsheet Word ProWordPerfectMicrosoft WordWord processing Lotus SmartSuiteWordPerfect Office 12 Microsoft Office

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 49 Web Technology: A New Way to Share Files Web technology refers to applications that enable the user to create documents that are compatible with the formats used on the Internet  The most common format is Hypertext Markup Language (HTML)‏ Microsoft’s.NET is designed to create universal communications between computers

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 50 System Requirements System requirements refers to the minimum level of equipment needed to run a program  Platform– PC or MAC  Microprocessor  Drive– 3.5 Floppy or CD-ROM  RAM  Available hard disk space Sample Minimum System Requirements IBM compatible PC with a 486 PC processor or better (Pentium® recommended)‏ Microsoft Windows® MB RAM (16 MB recommended)‏ Hard disk space (standard installation approx. 100 MB)‏ CD-ROM drive (2x or better)‏ Mouse or other pointing device

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 51 Software Version Software producers include a version number with their products Version numbers identify the release of the program being used Recent releases have numbers greater than earlier releases (Recent Ver. 6.0; Earlier Ver. 1.0)‏  Whole numbers are major revisions (1.0, 2.0, 3.0, etc.)‏  Decimal numbers refer to maintenance releases or updates and fixes (1.1, 1.2, 1.3, etc.)‏

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 52 Software Upgrades Software upgrading is the process of keeping the application program current Types of upgrades:  Patch – Small changes in the program  Service release or service pack – Major changes in the program

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 53 Distribution and Documentation Two methods of software distribution:  Shrink-wrapped boxes containing CDs or floppy disks  Downloading program files using the Internet Documentation includes tutorials and reference manuals that explain how to use the program  ReadMe files – Helpful information about the program  Help screens – On-screen program documentation

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 54 Software Licenses and Registration A software license gives the user the right to install and use the program on one computer Organizations purchase a site license to install a program on many computers

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 55 Commercial Software, Shareware, Freeware and Public Domain Software Most computer software is copyrighted Software piracy – Infringing on a program’s copyright  Copyrighted software can not be:  Copied  Altered  Used on more than one computer

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 56 Commercial Software, Shareware, Freeware and Public Domain Software Types of copyrighted software:  Commercial – Buy before using it  Shareware – Try it before you buy it  Freeware – Free software, but it can’t be copied and/or sold Public domain software is not copyrighted. There are no restrictions on using, copying, altering, or selling the software

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 57 Installing and Managing Application Software Installing Applications: Install the software on the hard drive  Installation utilities guide you through the process  Installation changes the registry of the operating system

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 58 Installing and Managing Application Software Use an uninstall utility to remove a program from the hard drive  Do not just delete a program from your files

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 59 Launching Applications: Launching a program transfers program code from the hard disk to the memory The program’s default window appears on the screen Installing and Managing Application Software

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 60 Applications can be launched by clicking on the Start menu, pointing to All Programs, and choosing the application Installing and Managing Application Software

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 61 Chapter 5 Summary Application software enables users to create, communicate, and be entertained The most popular general-purpose applications are personal productivity, multimedia and graphics, Internet, and Home and Educational Standalone software includes only the software tool you need. Integrated programs are aimed at beginners Office suites may incorporate Web technology

Computers Are Your Future Chapter 2 © 2006 Prentice-Hall, IncSlide 62 Chapter 5 Summary Publishers often bring out new and updated versions of their software Copyrighted software includes:  Commercial programs  Shareware  Freeware To use a computer successfully, you should learn how to start, install, launch, and exit applications