Lecture1
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The document provides an introduction to key concepts about how the web works. It explains that to use the web, a user needs a computer connected to the internet through a modem, network card, or wireless connection. The computer also requires web browser software and must be logged into the web through a service provider. Once logged in, the computer is assigned an IP address to identify its location. When a user enters a URL to request a web page, their IP address is sent along with the request so the page can be routed back to them.
Lecture1
- 1. Introduction to Web Introduction to Web Technology IT1 Course Slide Instructor: Majid Taghiloo
- 2. Purpose The purpose of this presentation is to: • Acquaint you with the terms and concepts necessary to determine how the Web can improve your business • Demonstrate the capabilities of Web applications p pp “It’s time to take the red pill” It s time to take the red pill
- 3. Web Concepts p How the Web Works Let’s start with you. the user • To use the web you must have a computer or another “web‐ready” device, ex: Palm Pilot or web ready Web phones*. *Often called Web Access Protocol (WAP) devices
- 4. Web Concepts p How the Web Works • Your computer must have communications hardware with installed drivers (software) – Modem card, ex: 56k Modem – Network* or NIC** card, ex: Linksys – Wireless Network card * Most networks today communicate using * M t t k t d i t i Transmission Control Protocol/Internet Protocol (TCP/IP) ** Network Interface Card
- 5. Web Concepts p How the Web Works • Your computer must have Web service – Modem and Dialup Internet Service Provider (ISP), ex: AOL – *Digital Subscriber Line (DSL), offered by phone company in non‐rural areas – *Internet Satellite, offered by satellite TV – *Digital Cable, offered by cable TV g , y – *Dedicated LAN, ex: large corp. networks or US govt. govt *These faster services are called “Broadband”
- 6. Web Concepts p How the Web Works • Your computer must have Web browser software – AOL Online Software – Microsoft Internet Explorer – Netscape Navigator – Other web services require mail programs (Outlook) or File Transfer programs p g (WS_FTP)
- 7. Web Concepts p How the Web Works • Your computer must be logged into the Web – Dialup has dialed, connected & user has logged in OR – DSL/Satellite/Cable modem is on and connected
- 8. Quick Note on Networks Simple Dialup There are many types of network setups • 56k Modem plugged into phone line (1 computer) • AOL i a di l service is dialup i Phone Dialup Outlet Modem Computer Note: Uses regular(RJ11) regular(RJ11) phone cable
- 9. Quick Note on Networks Simple Cable/Satellite • Cable/DSL/Satellite Modem plugged into cable/DSL/satellite outlet (1 computer) ( p ) • Charter and SBC/Yahoo are broadband Internet services Cable/DSL/ Cable/ Satellite Satellite Modem Outlet Computer Note: Uses special Category 5 Note: Uses special Category 5 *Most network equipment Most network equipment (Cat 5 RJ45) has a speed of 100Mbit/s Cable called patchcords
- 10. Quick Note on Networks Cable/DSL/Satellite with Hub • Cable/DSL/Satellite Modem plugged into cable/DSL/satellite outlet • Requires 2 or more Internet Protocol (IP) connections (like 2 separate phone numbers) Cable/DSL Cable/DSL Satellite Satellite Hub Computer Modem Outlet Computer
- 11. Quick Note on Networks Cable/DSL/Satellite with Router/Switch • Cable/DSL/Satellite Modem and Router/ Switch* plugged into cable/satellite outlet p gg • Requires only 1 Internet Protocol (IP) connection (shares a phone number saves $$) number‐saves Cable/DSL Cable/DSL Satellite Router/ Satellite Modem Switch Computer Outlet Computer *Switches are smarter and faster than hubs
- 12. Quick Note on Networks Cable/Satellite with Wireless Router/Switch • Cable/Satellite Modem and wireless Router/Switch plugged into cable/satellite outlet • Replaces switch‐to‐computer cables, requires wireless network cards* Wireless Cable/ Router/ R t / Cable/ Computer Satellite Switch Satellite Modem Outlet *Wireless is more convenient, but slower and less secure than Cable Computer
- 13. Quick Note on Networks Cable/Satellite ith Wireless and R l C bl /S t llit with Wi l d Regular Router/Switch • Cable/Satellite Modem and two Router/ Switches plugged into cable/satellite outlet Wireless Router/ Switch Computer Cable/ Computer Cable/ Satellite Satellite Modem Outlet Router/ Switch Computer C Computer
- 14. Quick Note on Networks Firewalls Firewalls are like the firewall in your car, which keep the heat and noise of the engine outside the passenger compartment noise of the engine outside the passenger compartment • Computer Firewalls are used to keep unwanted Internet users from accessing your network • Once online, you are vulnerable w/o a firewall – BlackIce is an example of firewall software Firewall Cable/ Router/ Cable/ Satellite Switch Satellite Modem & & Outlet Firewall Computer
- 15. Quick Note on Networks Firewalls • Computer Firewalls work like Caller ID • You set up the rules of who can “call” you • Unrecognized callers are either denied or asked denied, for a password NOTE: Some software, like PCAnywhere and SQL Server require the firewall to specially q p y configured
- 16. Web Concepts p How the Web Works Back to the Logged in computer Once your computer is logged in, it is assigned an Internet Protocol (IP) address. • Most networks (and all dialups) issue IPs on a per‐ login basis, these are called Dynamic IPs • Some networks issue these permanently, these are called Fixed IPs • Your IP is a 16‐digit number which is used to identify your computer to the Internet, ex: 208.127.007.123
- 17. Web Concepts p How the Web Works • Every time you request information from the Internet, your IP is sent with the request, so the I IP i ih h h Internet knows where to send the information • Every website has an IP address. The Universal Resource Listing (URL) like, www.yahoo.com is translated to its IP address automatically for you / NOTE: Remember the router/switches that only y need one IP address? The router keeps track of the network users so they can share the IP y address.
- 18. Web Concepts p How the Web Works Example: • You wants news so you types in: You wants news so you types in: http://www.msnbc.com/news/934483.asp?vts=07292003092 0 Quick Note on four parts of the URL: Q i kN f f h URL • Protocol: http is Hypertext Transfer Protocol, you will also see p y , https used for secure transactions. If you leave this off, the default is http. • Domain: www.msnbc.com identifies a specific webserver • Fil I f File Information: /news/934483.asp identifies the specific ti / /934483 id tifi th ifi filename on the requested website. • Query string: ?vts=072920030920 Additional information sent y g in the request, in this case the article number called vts.
- 19. Web Concepts p How the Web Works Simple Example: • You wants news so you type in: http://www.msnbc.com/news/934483.asp?vts=0729 20030920 • MSN‐BC receives the request, looks up the article and MSN BC receives the request, looks up the article and send it back to you. http://www.msnbc.com/news/934483.asp?vts=072920030920
- 20. Web Concepts p How the Web Works Detailed Example (what really happens): • You (208.127.007.123) want news so you type in: http://www.msnbc.com/news/934483.asp?vts=07292003092 0 • MSN‐BC’s IP address of 207.46.150.21 is translated by a MSN BC s IP address of 207.46.150.21 is translated by a program called the Domain Name Server (DNS) • The request is sent to http://207.46.150.21/news/934483.asp • MSN‐BC receives the request, accesses its database to look up i h i d b l k the article and sends the article (vts=072920030920) and several graphics* back to you (208.127.007.123) • Your browser assembles the article and graphics according to the HyperText Markup Language (HTML) code to format and display the MSN BC screen. display the MSN‐BC screen. *Each webpage is comprised of numerous graphic files, that why we see (10 items remaining) on the status bar of a downloading page. It’s waiting for those pieces to complete the page.
- 21. Web Concepts p How the Web Works Detailed Example (Other Comments): • Technically the Internet is a large network. The Worldwide Technically the Internet is a large network. The Worldwide Web (WWW) is an application that runs on the Internet. Whenever you type in “http://www.whatever.com” you are using the Worldwide Web. The Worldwide Web produces using the Worldwide Web The Worldwide Web produces webpages (a combination of text and graphics). • MSN‐BC’s website has an IP address of 207.46.150.21. It uses MSN BC s website has an IP address of 207.46.150.21. It uses the domain name of www.msnbc.com because it registered that domain name with Network Solutions or another authorized Domain Registry company. These companies authori ed Domain Registry company These companies maintain the databases used by the Domain Name Servers (DNS). Current annual fees are about $35.
- 22. Web Concepts p How the Web Works Detailed Example (GeeWhiz Stuff): • Network messages are split up and transmitted in small Network messages are split up and transmitted in small sections called “packets”. TCP/IP is a “packet‐switched network”. • JavaScript, Java and Perl are languages uses to help HTML display webpages (scrolling display, animation, etc). More on this when we talk about Web Applications. • Flash, Shockwave, Quicktime, WAV, mpeg, RealAudio, and MP3 are all types of files that can be displayed with a webpage. Special programs, called “plug‐ins” allow your browser to display, play, or run these various files. browser to display play or run these various files
- 23. Web Concepts p How the Web Works Detailed Example (Security): • Webpages are secured by installing a special license and software are secured by installing a special license and software, called a Secure Socket Link (SSL) on the servicing website called a Web Host. This software encrypts communication between the user computer and website. Most credit card processing is transmitted using SSL. You’ll notice the protocol will be https:// or shttp:// and a secure or locked icon appears on your browser screen a “secure” or “locked” icon appears on your browser screen. Current annual fee is about $400. • Hackers monitor web requests using special software, SSL q g p , $$$ protects financial & personal information by encrypting these messages—foiling the hackers. https://www.bankofamerica.com
- 24. Transmission Speed Transmission Speed is the amount of data that a line can transfer transfer. • A 28.8k modem transmits 28,800 bits per second ( p ), (bps), a 56k modem transmits 56,000 bps ( , p (7 kbytes/s) – the maximum via normal phone lines • An ISDN modem transmits 128k • Cable/Satellite/DSL transmit at least 384 kbps • A T1 line transmits 1.54Mbps (ISP speed) • A T3 line transmits 43 Mbps (Web host speeds) • Fiber Optics start with OC‐3 which is 115 Mbps • OC‐12 is 622 Mbps (Internet backbone speed)
- 25. Search Engines All search engines do about the same things: • Search the Internet for websites using robots which are robots, automated software programs that search for keyword and description META tags in the HTML code • Allow users to search their database using keywords • Allow website administrators to suggest their sites to the search database (no guarantees) • Allow website administrators to buy “premium placement” – Extra money to get to the top of the list y g p • Other companies, like Overture, also manage premium placement or sponsored links for search engine sites.
- 26. Web Applications • Web pages are like online Word documents. HTML is used to display pictures format paragraphs change pictures, paragraphs, colors, fonts, etc.. BUT Word can’t add numbers or animate graphics. • Web Applications are like online spreadsheets and databases. They do something. Common scripting languages used to do this are Cold Fusion Active Fusion, Server Pages (ASP), and PHP. • Web Applications interact with program variables variables, databases, spreadsheets, and user inputs to create dynamic web content.
- 27. Web Applications • In fact, our first example was a web application li ti • When the MSN‐BC server read the 934483.asp file, control moved to the ASP server and passed the variable VTS with a value of ASP ASP Server Server 072920030920 VTS=072920030920 http://www.msnbc.com/news/934483.asp?vts=072920030920
- 28. Web Applications • The 934483.asp file searched the news database for article number (VTS) 072920030920 VTS=072920030920 Database ASP ASP Server Server VTS=072920030920 http://www.msnbc.com/news/934483.asp?vts=072920030920
- 29. Web Applications • The article text is passed back to the ASP Server • Then to the MSNBC web server VTS=072920030920 Database ASP ASP Server Server VTS=072920030920 http://www.msnbc.com/news/934483.asp?vts=072920030920
- 30. Web Applications • The article text is then inserted into the web page and sent to the requesting user VTS=072920030920 Database ASP ASP Server Server VTS=072920030920 http://www.msnbc.com/news/934483.asp?vts=072920030920
- 31. Web Applications • Web Applications can read or write to multiple databases, sp eads eets, e e mail servers to spreadsheets, even a se e s send email confirmations Database Spreadsheet ASP Server Database Mail Server Web Server
- 32. Web Applications Web Applications include on‐line: on line: • Banking services • Catalogs and shopping carts • Airline ticket reservations • Ch rooms Chat • Message Boards • Search Engines • Theater Listings • Dating Services • Mortgage Calculators g g To name only a few applications.
- 33. E‐Commerce E Commerce E‐commerce sites are basically large web applications. The ordered items go into a database, which adds up the prices, taxes, , p p , , even shipping. The tricky part is the credit card processing Let’s follow a user that is placing an order.
- 34. E‐Commerce E Commerce • First, the user goes to a website User and adds her desired items to the shopping cart • When all her desired items are in the shopping cart, she clicks the h h i h li k h Web Secure “checkout” button Server Web Server • The web application will total the item quantities and prices, Verification Svc determine taxes, shipping , pp g charges, and present an invoice to Website’s her. IMA Bank Bank Acct
- 35. E‐Commerce E Commerce • Next, the she reviews his order User and clicks the Purchase button • The order request is received by the web server who talks to the h b h lk h Web Secure Server Web secure web server Server • The secure* web server sends a Verification Svc secure web page to accept the credit card and personal Website’s information IMA Bank Bank Acct *Most Web Host offer limited free SSL services to their customers
- 36. E‐Commerce E Commerce • She then inputs his credit card User information and address and starts the credit card purchase • The credit card information and address is verified b the Verification dd i ifi d by h ifi i Web Secure Service, (ex: VeriSign) Server Web Server • The Verification Service acts as a messenger service couriering verified Verification Svc information and money to the y required places IMA Website’s • Verification Services cost about Bank Bank $20/mo $20/ Acct
- 37. E‐Commerce E Commerce • The verified credit card voucher is User forwarded to the Internet Merchant Account (IMA) bank • Th website h an IMA to cash the The b i has h h Web Secure Server Web credit card vouchers. These IMA Server banks h b k charge a percentage and a per d Verification Svc transaction fee. They also have a minimum f of $20/ i i fee f $20/month so if you h Website’s only receive a few credit card IMA Bank Bank transactions, you’ll end up paying a i ’ll d i Acct larger fee
- 38. E‐Commerce E Commerce • The Internet Merchant Account bank User will “cash” the credit card request, cash request subtracting their 2‐3% and 25‐35 cents/transaction charges Web Secure Server Web • The proceeds are deposited into the Server Website’s b k W b i ’ bank account Verification Svc • This bank account can be the website company’s regular business bank Website’s account or a separate one IMA Bank Bank Acct
- 39. E‐Commerce E Commerce • The Internet Merchant Account bank User acknowledges the transaction to the Verification Service • Th V ifi i S i acknowledges The Verification Service k l d Web Secure Server Web the transaction to the Web Server Server • The Web Server sends notice to the Verification Svc user that her transaction was approved (or disapproved) Website’s IMA Bank Bank Acct
- 40. E‐Commerce E Commerce • The Verification Service will also User notify the Website owner of all credit card transactions • All credit card activities are saved i a di d i ii d in Web Secure Server Web database. Special administrative Server webpages ( b (passworded) allow the d d) ll h Verification Svc website owner to reconcile credit card activity, perform charge‐backs, d i i f h b k Website’s and notify additional email addresses IMA Bank Bank of account activity f i i Acct
- 41. Website Requirements Requirements Collection • One of the most important steps • How do we, the development experts, collect we experts requirements from a businessperson who knows his b k h business—but not the Web? b h b?
- 42. Website Requirements What Do You Want the Web to do for you? • What information, pictures, prices, etc. do you want to show about your company? • Do you want to sell products or services from your website? b ? • What information could you put on the Web y p that would prevent “time‐costly” phone calls?
- 43. Website Requirements What Do You Want the Web to do for you? • What web applications would bring more business to your company or make your personnel more efficient? – Tying information from multiple databases together y g p g into a single report – Extending your business information and gy applications to your “on the road” salespersons or technicians – Automating boring, labor‐intensive tasks
- 44. Website Requirements q What do I need for my Website? • Web Host* – Web server where your website is hosted. hosted Prices are $10 ‐ $50 /mo depending on languages supported, databases, etc. • Domain Registration – Registers your named URL, g g y , www.business.com Prices are $10 – 35/year. • Web Design ‐ Designing the content, navigation, and layout of your website (f l f b i (front‐end). P i d) Prices are $50 ‐ $150/hour. • Web Applications – Design web application functionality (back‐end). Prices are $65 – $250/hour *This is not your Internet Service Provider (ISP). Although your ISP may also Web Host.
- 45. Website Requirements W b it R i t What do I need for my Website? (Cont’d) If e‐comm/credit card processing is required: • Shopping Cart Software, ex. Miva, AbleCommerce, or custom Prices are $1000 ‐ ? • Verification Services, ex. VeriSign Prices are a one‐ time setup fee ($150) and about $20/month • Internet Merchant Account (IMA), ex. eMerchant Solutions Prices are a one‐time setup fee ($ ) and 2‐3% p ($100) and 25 cents per transaction • PayPal, requires user signup and checking information y , q g p g