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Intro to Information Systems I

Intro to Information Systems I. Web Publishing & Information Systems ISYS 101 Glenn Booker. The Internet. Over 60% of Americans use the Internet regularly Media are converging on the Internet – radio stations, TV, telephone, and newspapers all are online

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Intro to Information Systems I

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  1. Intro to Information Systems I Web Publishing & Information Systems ISYS 101 Glenn Booker Lecture #4

  2. The Internet • Over 60% of Americans use the Internet regularly • Media are converging on the Internet – radio stations, TV, telephone, and newspapers all are online • Commerce is taking place on the Internet, aided by higher levels of security Lecture #4

  3. The “internet” • Private networks also exist which use the same protocols as the Internet – these private networks are internets • Government and large corporations create internets to support controlled exchange of data Lecture #4

  4. Interoperability • The Internet works because many different kinds of computers (PC’s, Macintoshes, Unix workstations, mainframes, etc.) all speak the same languages – TCP/IP • The Internet grew out of the need to get four very different computers to communicate, so scientists could share information Lecture #4

  5. Other Internet Access • Online services, such as AOL or Prodigy, add their own custom applications on top of standard Internet applications • “Portals” are Internet sites which add some features to encourage people to use them • Yahoo, Excite, Google, and Go are examples Lecture #4

  6. Internet Growth • The Internet grew quietly from 1969 through the 1980’s • Invention of the World Wide Web, an Internet application, brought the Internet into public awareness around 1994 • That’s about when the “information superhighway” term was coined Lecture #4

  7. Client versus Server Services • Important to distinguish which Internet Services are done by the server (who hosts the web page, for example) and which are done by your computer (the client) • Affects download time, and the amount of work the server has to be able to handle • Most services are done by the server Lecture #4

  8. Internet Services • Most familiar are e-mail and the WWW • Use e-mail addresses and URL’s, respectively to define where someone or something is on the Internet • E-mail applications include Outlook and Eudora • WWW application include Internet Explorer and Netscape Communicator Lecture #4

  9. Internet Services • FTP was designed specifically for transferring large files between computers • Downloading refers to copying files to the client • Uploading copies files to the server • FTP can be limited to specific users (via a login name and password), or anonymous FTP can be used, which allows anyone in Lecture #4

  10. Internet Services • Usenet contains thousands of newsgroups which allow people of many common interests to find each other easily • Servers for Usenet are also called NNTP servers • Newsgroups are mostly grouped into hierarchies: alt(ernative), comp(uter), sci(ence), misc, soc(ial), news, and rec(reational) Lecture #4

  11. Internet Services • IRC is the original chat application • Chat groups are on channels • Communicate by typed text • Newer variations include AOL Instant Messenger (AOL IM), ICQ, Yahoo chat, and MSN’s chat program Lecture #4

  12. Internet Services • Internet-based telephone and video services now exist too • Quality and resolution aren’t great, but they’re free! • Corporate uses include video conferencing • Examples include WebCam and CuSeeMe Lecture #4

  13. Internet Services • Telnet allows logging into a remote computer • Ping asks if another computer is online • Archie is a search tool for FTP sites • Gopher was a menu-driven document display tool used by libraries and schools • Veronica was a Gopher search tool Lecture #4

  14. Internet Access • Most analog modem-based connections to the Internet use the PPP protocol • The Slip protocol is obsolete • Shell access is a text-only Unix login • Most users don’t get a fixed IP address on the Internet – your IP address is assigned when you log in (dynamic IP) Lecture #4

  15. Internet Access • Most home users who aren’t on modem access use a cable modem or DSL • Businesses tend to use an ISDN or T1 connection (if not faster) • Each computer on their LAN gets to the Internet through a router Lecture #4

  16. Internet Addressing • Internet addresses are given by the Internet Protocol (IP) in the form of a “dotted quad” – four numbers from 0 to 255 which are separated by periods, such as 23.124.65.222 • IP addresses are converted to and from URL’s (e.g. www.microsoft.com) by the domain name system (DNS) Geek Comment: If you watch “The Net”, they show an IP address for the bad guy which isn’t a legal IP address! Lecture #4

  17. Internet Addressing • A higher level of communication on the Internet is handled by the TCP protocol • Once another computer’s IP address has been found, TCP manages the actual connection between the computers (like logging in and getting data) Lecture #4

  18. Domain Names • There are seven top level domains (TLD): • Commercial (com) • Education (edu) • Nonprofit organizations (org) • Military (mil) • Network organizations (net) • International organizations (int) Lecture #4

  19. Domain Names • In addition, each country has a domain • United States (us) • Canada (ca) • And so on… • Top level domain names focus on the type of organization instead of the type of web page content Lecture #4

  20. Domain Names • New domains are being released (probably): • name for personal pages • biz for businesses • coop for cooperative businesses • aero for the aerospace industry • museum for museums • info for anybody • pro for professionals (lawyers, accountants, ...) Lecture #4

  21. The Future of IP • A new version of IP, called IPv6 or IPNG (for IP Next Generation), is becoming available • Makes the IP address go from 32 bits (four groups of 8 bits each) to 128 bits (eight 16-bit groups); an IPv6 address could be: FEDC:BA98:7654:3210:FEDC:BA98:7654:3210 (In 16-bit “numbers”, the letters “A” to “F” mean “10” through “15”) Lecture #4

  22. Hypermedia • The hyperlink made it possible to make any text into a link to jump to another document • Now systems are developing which will automatically recognize common terms, and make them a link to some (hopefully) relevant reference material • So ‘giraffe’ might link to an encyclopedia entry Lecture #4

  23. Hypermedia • Early web browsers were text only (such as Lynx) – later graphics, sound and video were added • The first graphical browser was Mosaic • A computer which runs a web service is a web server – all web pages are located on a web server somewhere Lecture #4

  24. Web Protocols • Web pages use the HTTP protocol, which understands pages written in HTML • HTML describes how text and images should be displayed – can be similar to using styles in Word (title, bulleted list, etc.) Lecture #4

  25. E-commerce • More and more business is being done over the Internet • Businesses have started catering to each other, and not just the mass consumer • EDI is an older form of business-to-business networking specifically to conduct transactions over the Internet Lecture #4

  26. Shopping Online • Internet-based consumer shopping has grown wildly in recent years • Key challenges are finding ways for customers to find you (the Internet is big!), and maintaining enough stock to cater to common purchases • Offers more selection and sometimes better prices than brick-and-mortar stores Lecture #4

  27. Secure Transactions • Most credit card transactions over the Internet use some form of secure transmission to avoid theft of data • Some stores get a certificate of authority (CA) to conduct secure transactions • Others use a third party to ensure privacy, like PayPal Lecture #4

  28. Online Banking • Banks and other businesses have discovered online transactions too • Banks, utility companies, credit card companies, and many others can do business over the Internet • Stock and bond trading is also done online (Ameritrade, e-trader, etc.) Lecture #4

  29. E-mail • E-mail is a major Internet service • A server runs different e-mail functions • Your computer runs a client to get your mail from the server, and send outgoing mail through the server Lecture #4

  30. E-mail Protocols • SMTP is used to send and receive text messages by e-mail • POP stores incoming messages until you download all of them at once (from the server to your client) • IMAP allows you to screen messages and delete some from the server, so you never have to download them Lecture #4

  31. E-mail Clients • E-mail clients include Microsoft Outlook and Eudora • E-mail services are also available via the WWW (e.g. Hotmail, Yahoo mail, etc.) • Most clients also allow encryption to be used to improve security, or you can digitally sign documents Lecture #4

  32. E-mail Attachments • E-mail attachments are handled using a protocol called MIME • Beware of attachments which are executable files (*.exe) or Visual Basic macros (*.vbs) – they need to be checked for viruses! • Keep attachments small (fraction of 1 MB) Lecture #4

  33. E-mail Filters • Filters can be used to automatically route e-mail to specific folders, or delete spam (unwanted e-mail) • Mailing lists can help send mail to lots of people at once (e.g. an entire class) Lecture #4

  34. Creating Web Pages • A web site needs a clear purpose and audience • Many HTML editors are available to help create your web site • A web site is composed of one or more web pages Lecture #4

  35. HTML Editors • Popular HTML editors include: • Microsoft FrontPage • Macromedia Dreamweaver • Adobe PageMill and GoLive • Netobjects Fusion • Allaire Homesite; Netscape Composer • Spiderwriter; HotDog; and others Lecture #4

  36. HTML Editors • Text editors, such as NotePad or WordPad can be used to write HTML manually • Some word processing programs can convert documents to HTML, but often badly (e.g. Word) • Professionals may create a page with an HTML editor, then fine tune the HTML by hand Lecture #4

  37. Web Site Purpose • Why would someone come to your web site? • To learn about you • To learn about some subject • To buy something • To socialize • To hire you • Or something else? Lecture #4

  38. Web Site Design • Several fundamental design decisions need to be made about a web site • The course’s web site uses a simple menu-driven structure – boring but effective • Frames can be used to put defined structure in specific areas, but aren’t readable by all web browsers Lecture #4

  39. Web Site Design • Some programs (e.g. FrontPage) use “shared borders” to provide continuity from page to page, and to help navigation • Cascading style sheets (CSS) can help your site achieve a consistent look across many pages without editing each page separately for font size, style, etc. Lecture #4

  40. Web Site Design • Your design should consider how the site will be viewed – what screen size will be used by a typical user?E.g. 800x600 pixels is a typical size • Color is a separate issue – some colors are viewable by all graphic web browsers; these are called web safe colors, and there are 216 of them Lecture #4

  41. Web Site Design • What download speed will the user have? • 56 kb modem (maybe less if in a lesser developed country) • 128 kb ISDN • T1 or cable modem • What languages will your users need? Much of the world doesn’t speak English! Lecture #4

  42. HTML • HTML describes how the page is laid out • An HTML document is a text file which describes the contents of the document, and how they should appear • Some HTML content does not appear on screen • The program which used to create the page • Search criteria to help people find the page Lecture #4

  43. HTML • Other HTML describes the background, or tells where to find images to put in the page • HTML can include hyperlinks to documents, files, images, movies – anything you can put on a computer • Be warned that HTML ignores extra spaces and manual line or page breaks Lecture #4

  44. HTML • HTML can include • Numbered lists (1, 2, 3, …) • “Unnumbered” lists (bullets) • Structure makes a document easier to read • HTML can include e-mail contacts • HTML images should be in GIF or JPG format – do not use BMP files (bitmaps) Lecture #4

  45. Forms and Scripts • Web pages can use forms to collect data (like requests for sales calls) or display the results of database queries (like a list of the Macintosh-compatible video cards for sale) • Programming languages such as Java and JavaScript can be used for more complex activities Lecture #4

  46. XML • XML is an emerging markup language • Instead of defining the format of a document’s contents, it describes the type of contents • For example, XML tags could describe a zip code, or street address, or catalog number Lecture #4

  47. XML • The meaning of the tags can be defined in a style language, which can even define what tags can be used, and the order in which they may appear • This helps search engines understand the difference between, for example, a site featuring Roll Over Beethoven and one dedicated to Ludwig van Beethoven Lecture #4

  48. More Web Resources • For more on web design, see • HTML Writer’s Guild • Web Pages That Suck • The Reference section of my web site has more resources on XML Lecture #4

  49. Information Systems • Vast amount of data are generated every day • The challenge of information systems is to organize that data and help find the ways it can be useful • We call them “systems” because all aspects are needed to produce useful information Lecture #4

  50. Information Systems • Information systems consist of: • Software • Hardware • People who create, maintain, and use them • And the documents which describe what the hardware and software do, and how the people use and maintain them • It’s not just software or a database! Lecture #4

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