计算机导论讲.pdf

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1、1.INFORMATION TECHNOLOGY,THE INTERNET,AND YOU1.The purpose of this book is to help the student become computer literate Competent in computer-related skills The goal is to be valuable immediately to a potential employer Chapter one gives an overview of an infonnation system This system consists of t

2、he following:People Procedures Software Hardware Data4.Define an information system Some students may think of a system as pertaining to just the hardware Remind them that a microcomputer is part of an information system To be competent end user,one must understand the essentials of IT Note that IT

3、stands for information technology5.People are the most important part of an information system Our lives are touched everyday by computers Have students give examples of how they use computer applications throughout the day Some examples are:instant messaging Web-based applications personal website

4、virus protection TV tuners and video clips digital photography music home networking spyware job opportunities6.Emphasize differences between application and systems software System software operating system utilities device drivers Application software general purpose special purpose7.Software is a

5、nother name for programs Programs are instructions that tell the computer how to process data into the form youwant Two major kinds of software System Not a single program a collection of programs Operating systems Windows XP Mac OS X Utilities Service programs Performs tasks related to managing com

6、puter resources Device drivers Application8.“End-user*software-people who use microcomputer or have access to larger computers Nearly everyone in todays workforce and general public have access These people enter commands and typically interact with application programs.Two major categories General-

7、purpose or basic programs;off-the-shelf Specialized-written for an organization or business types specific purpose;specially written9.Examples of hardware:Disk drive,keyboard,printer and modem are different types of computer hardware10.There are four types of computers Supercomputers Mainframe compu

8、ters Minicomputers Microcomputers desktop laptop or notebook tablet PC Handheld computers Palm computers Persona digital assistants11.Above is an example of a Cray supercomputer,which,unlike the illustration,is always inan air conditioned box This is required because of the heat generated during pro

9、cessing A major reason fbr its processing speed is shorted connection wires throughoutthe interior Of course,shorter wires means faster byte transfer times12.13.14.15.16.17.Supercomputers are the most powerful type of computerNASA uses supercomputers to track and control space exploration Mainframes

10、 occupy specially wired,air-conditioned rooms Not as powerful as supercomputers Insurance,financial and equity industries,as well as governments all process largeamounts of information on mainframes These are refrigerator sized machines Production departments use minicomputers to monitor certain man

11、ufacturing processesand assembly line operation s Problem is most current desktops have capacity of many minicomputers.Lease powerful computers,but most widely usedFastest growing computerHave students begin discussing the microcomputer and wireless connectivity System Unit Memory CPU I/O Devices Mo

12、nitors Printers Secondary Storage Floppy Hard drive Optical disksMonitors include LCD panels and traditional CRTs.Current trends regardingmonitors;sizes depending upon use of system Communications Modems-equipment that translates data from the CPU to a form humans canunderstand Used to describe fact

13、s about something Contained in files for documents,worksheets and databases Document files-usually created by word processors Worksheet files-electronic spreadsheets Database files-electronic database management programs Presentation Files-electronic slides shows Connectivity is the capability of yo

14、ur microcomputer to share information with othercomputers Wireless/mobile communication devices are more popular than ever A network is central to the concept of connectivityAsk students questions about the Internet.Here are some facts:No one owns the Internet There is no Internet,Inc.The Internet i

15、s a network of networks The WWW provides multimedia interface to resources on the Internet18.Using information technology means being computer competent The Internet and the Web are the two most important technologies of the 21 st century Software can now do extraordinary tasks Microcomputers are mo

16、re powerful Society must be careful about protecting their privacy Almost all organizations rely on information systems2.THE INTERNET,THE WEB,AND ELECTRONIC COMMERCE1.Ask the students why the Internet is often referred to as the Information Superhighway Competent end users need to be aware of the re

17、sources available on the Internet and theWeb Ask students to list the resources they use on the Web3.Most developed network system currently in use;connects people all over the world Originally started in 1969 when US funded a research project(ARPANET).CERN-Center for European Nuclear Research World

18、 Wide Web(Web)is a part of the Internet-not the Internet;introduced in 1992 byconsortium in Switzerland.Originally started as research and text-based network to exchange research ideas fromuniversity to university Developed into a network of networks One of the most powerful tools of the 21st centur

19、y4.Most common Internet applications Communicating-sending e-mail and discussion group participation You can chat live with others Ask students what chat software they use Shopping-fastest growing applications Searching-using virtual libraries Entertainment-increased use of DVD;integration of TV and

20、 PC Education ore-learning You can take classes on almost any subject5.,The common way to access the Internet is through a provider or host computer Providers-already connected to the Internet-furnish a pathway for other users Typical providers include:Colleges and universities-usually free”Internet

21、 service providers QSP)can be local(regional)or national Ask students to identify various ISPs used in their environment Types of providers National-like AOL Regional-smaller service area Wireless no telephone lines used provide connection through wireless modems6.Browsers allow you to search or sur

22、f the Web Navigate search for information and communicate using the Web Use URL(uniform resource locator)to connect to other resources Two parts to URL:protocol(usually http:/);second is domain name or server whereresource located()7.Browser is software that allows users to navigate the Web and read

23、 the multimediaformatted pages Connect to Web sites using URL addresses(uniform resource locator),Document is sent to computer usually coded in HTML(hypertext markuplanguage)or some variation Interprets the HTML codes displaying page May contain Hyperlinks-allow users to quickly connect to other pag

24、es or Web sites Graphics Text8.Web pages contain links to programs called applets These are special programs written in a programming language called Java These programs can be quickly downloaded and run by most browsers9.Communications is the most popular Internet activity Types of communications:E

25、-mail or electronic mail Transmission of electronic messages over the Internet Has three basic parts:header,message,and signature Header Address Subject-very important to include this in a message Attachments Spam-unsolicited e-mail Distraction Nuisance Discussion groups Participate in fbrums and de

26、bates Includes mailing lists,newsgroups,chat groups,and instant messaging Mailing lists-message is sent to a list of addresses Newsgroups-uses a special network called UseNet Chat-allows direct,live communications IRC-Internet Relay Chat is a very popular chatservice IM-instant messaging can send me

27、ssages back and forth in real time Lurking-this is a technique you can use before you participate in a discussiongroup You observe and dont respond until you feel more comfortable with thegroup Discussion groups10.The most common Internet activity With Internet access and an e-mail program,one can r

28、each anybody in the world similarlyequipped An e-mail message has three basic elements Header-subject,address and attachments Message Signature Internet addresses use the domain name system.Personal Information Managers-helps in organization and communication with others Electronic Day timers plus a

29、bility to communicate through Internet11.Internet uses the domain name system(DNS),which gives names and numbers to peopleand computers Address has three parts User name-identifies unique user or computer in the domain Domain name-references a specific organization Domain code-geographical location

30、or organizational identification Domain identification=.com=commercial=.edu=education and research=.org=organizations(usually non-profit),=.net=major network centers(usually easier to access than commercial)=.gov=government12.Mailing lists send e-mail to all members.Sign up Messages sentUnsubscribe

31、Newsgroups use the Usenet.Most popular discussion group Located on a special network called UseNet Chat groups support live conversations.IRC favorite of many users Allow live communication in real time Communication by typed messages Lurking is good-Reading communications before contributing Helps

32、potential participants understand the culture of the group Uses lists(instant messaging)to activate notification when live Must join,then sign on to participate Individual communication Group communication Use lists are more private than Chat groups13.Ask students to give examples of the each of the

33、 above discussion group terms14.Specialized programs that assist you in locating information on the Web and the Internet Search services(providers)help you locate information;they maintain the database thathelps you get where you want Special programs called agents,spiders,or bots,continually look f

34、or info and updatedservices Search engines-assist you to locate information,Examples AltaVista Excite Google Northern Light Teoma Yahoo!use keyword search;know“rules i.e.use+or quotes to lookfor phrases rather than individual words use directory search-list of categories or topics;also known asindex

35、 search Metasearch engines-programs that automatically submit your search request to severalsearch engines simultaneously.15.Keyword search-enter a keyword or a phrase Returns a number of hits Each hit includes a hyperlink Directory search Known as an index search Select a category or topic that fit

36、s the information you want Note:a recent study by the NEC Research Institute found that any one search engineincludes only a fraction of the informational sources on the Web16.Programs that automatically submit your search request to several engines simultaneously The engine receives the results,eli

37、minates duplicates,orders hits,and then provides theedited list to you17.Electronic commerce is buying and selling over the Internet Three basic types of electronic commerce:business to consumer;consumer to consumer;and business to business Web storefronts are virtual stores for B2C commerce;just li

38、ke being in the store exceptyou do it from home Web auctions growing in popularity;similar to traditional auctions-no one sees eachother Auction house sites-merchandise presented for auction Person-person auction sites-more like flea markets;forum for buyers andsellers to gather Electronic payment-e

39、asy,secure payment method Checks-slowest and least convenient Credit cards-Easier to work with,Somewhat vulnerable to theft Electronic cash or e-cash-also known as cybercash and digital cash Purchased from third party(usually a special bank);More secure thancredit cards18.Virtual stores for B2C elec

40、tronic commerce Shoppers visit stores on the Web to inspect merchandise and make purchases19.Similar to Web traditional auctions Buyers and sellers seldom meet face-to-face Ask the students if they have ever used E-bay20.A challenge is the payment for goods Should be reliable,secure,and fast21.Telne

41、t runs programs on remote computers;connect to another computer and runprograms on it FTP transfers files;file transfer protocol;Internet service for file transfer Downloading-transmitting files from the host to client Uploading-transmitting files from the client to host Plug-ins-automatically loade

42、d by and work with your browser;Acrobat Reader;Cosmos from Silicon Graphics(3-d displays);Media Player;Quicktime from Apple;RealPlayer;and Shock wave from Macromedia Helper applications are independent programs executed from your browser designed tomaximize your efficiency Off-line browsers-Off-line

43、 search utilities-auto submit your searchinfo to variety of engines and create an index for your review;auto saveHTML docs to your hard drive Information pushers-User selects topic areas or channels of interest Program retrieves relevant information from the Web and stores it for viewing atthe conve

44、nience of the user Filters-block access to specified sites;set time limits22.Internet2 is a collaborative project between an assembly of universities,the government,and private resource groups Faster downloads and less waiting time are some of the advantages3.BASIC APPLICATION SOFTWARE1.The microcom

45、puter can help you do many things-think of it as an electronic tool The right kind of software is needed4.Use the application for which it was designed:if you want to process text,use word If need to sort information,use database rather than spreadsheet Can create publications with Word;but presenta

46、tion software and desktop publishingsoftware ai-e designed to do this type of task easier Specialized Applications Called special purpose applications Common types Graphics Audio/video editors Multimedia creation Web authoring5.Common features of software User interface GUI-graphical user interface

47、Mouse and pointer Window Menus Pull-down or drop down menu bars Toolbars Buttons Standard toolbars6.Review the common toolbar commands with students,Open File Save Save As Print7.Web Based Applications Special sites called application service providers(ASPs)allow access to theirapplication programs

48、ASP-Application Service Provider Pay for actual use Only when accessed and used Eliminates need to upgrade8.One of the most flexible and widely used software tools One of the first programs used by PC end-users Used by most end-users9.Word wrap-automatically moves text to new line when prior line is

49、 full Enter overrides and starts new line,Incorrect spelling is identified and alternatives offered Identifies poor grammar and makes suggestions Quickly locate with search or find commands Automatic update of word(s)found with new word10.Report features,AutoCorrect Footnote Header or footer Caption

50、s and cross references Tables11.Analyzes and graphs numeric daa such as budgets and financial reports Electronic worksheet used to organize,manipulate and graph data;also known asworksheets Consist of grid of numbered rows and columns12.Values are numbers used for calculations;labels are letters,num