1. 1 Week 2 HTML Review, Summary of Chapters 1 & 2, Establishing a Web Presence Advanced Web Development IT225 Spring Term 2016 Marymount University School of Business Administration Professor Suydam

2. Review of HTML Summary of Chapters 1 & 2 Preparation for In-Class Exercise in Week 3

3. 3 Distinguish between the Internet and the World Wide Web (WWW) (W3) and provide a very brief history of each Explain client-server architectures, as illustrated by web browsers and web servers Discuss how web browsers and web servers communicate Take a brief look at a real-world e-commerce website Outline the technologies we will discuss in this text and mention some of the competing technologies Explain what an Internet Service Provider (ISP) is and what services you can expect from one Discuss what web development tools you need to get started Create a simple text-only web page Test a web page “offline” before going “online” Put a web page “online” by “uploading” it Discuss MIME (Multipurpose Internet Mail Extension) types and how browsers use them to determine the kind of document they are being asked to process

4. 4 The Internet Think hardware (“connected” computers/devices) Originated with ARPANET (late 1960s) The World Wide Web (WWW) (W3) Think software (users communicating over the Internet via software applications) Originated with Tim Berners-Lee and HTML, and took off with the first GUI browser, Mosaic Client-Server Architectures A “client” makes a request to a “server” The server’s response may be Compliance with the request, then breaks connection An error message indicating a problem Example A user’s browser requests a web page for display from a particular web site The web server at that site sends the web page or an error message (like a page-not-found error)

5. 5 The term “server” may refer to a program or the machine it runs on Current popular servers are Apache and Microsoft’s Internet Information Services (IIS) Every browser is a program that can act as the client in a client-server relationship Current popular browsers include: Chrome, Internet Explorer (Edge?), Firefox, Safari and Opera

6. 6 Source: W3C Counter Sarfari on Mac Safari for Windows no longer available Chrome on Windows Internet Explorer 11 on Windows Firefox on Windows Opera on Windows If you design a page, test it with all browsers to ensure it renders the same.

7. 7 Person-to-person telephone Telephone rings Callee answers and says “Hello” Caller self-identifies and states reason for call Callee responds appropriately Caller and callee exchange information Caller (or callee) says “Good-bye”, and the other responds likewise Both caller and callee hang up Browser and Server via the Internet User types address of web page into browser’s address bar and presses “Go” button Browser sends an HTTP request message to the server identified by the web address Server receives the request and sends back an HTTP response message If there was no error, the browser displays the content part of the response message

8. 8 Request An HTTP request from a browser contains A request line, with a request method (often GET or POST), the URI of the desired resource, and the version of HTTP in use Some header lines, indicating such things as language in use, encoding scheme, and so on A (very important) blank line An optional message body Response An HTTP response from a server contains A status line, indicating everything is OK or a number indicating that an error has occurred (404 not found, for example) Some header lines, providing information about the response, especially its content type A (very important) blank line The content of the returned web page or other resource

9. 9 TCP/IP is the fundamental protocol for most communication on the web UDP is fast and can be used if there is a lot of data and you don’t mind losing a few bits FTP is a file transfer standard TELNET provides a non-secure way to login to a remote computer SSH can be thought of as a “secure telnet”

10. 10 Every device connected to the Internet must have a unique IP address: IPv4 is 32 bits: a.b.c.d with a, b, c, d in 0..255 IPv6 is 128 bits, allowing for many more addresses Computers understand IP addresses much better than humans, who prefer FQDNs FQDN = Fully Qualified Domain Name FQDN cs.smu.ca has IP address 140.184.133.99 A Domain Name Server (DNS) translates between an IP address and the corresponding FQDN A Uniform Resource Locator (URL) is the actual location of a resource on the web A Uniform Resource Name (URN) has the same form as a URL but may not refer to an actual resource The term Uniform Resource Identifier (URI) is a generalization of the above two terms and may refer to either one.

11. 11 Internet Service Provider (ISP) A business or organization that provides you with an Internet connection You may have to pay, or it may be free The connection may be wired, or wireless Different ISPs provide different levels of service Wired Connection Options Dialup over regular phone lines via a modem Cable modem (usually from your TV provider) Integrated Service Digital Network (ISDN) Asymmetric Digital Subscriber Line (ADSL) Fiber-to-the-Premises (FTTP) Wireless Connection Options WiFi (at home and at downtown “hot spots”) Code Division Multiple Access (CDMA) allows bandwidth sharing of different frequencies Global System for Mobile (GSM), very popular for mobile telephone systems Worldwide interoperability for Microwave Access (WiMAX) for fixed and mobile Internet access

12. 12 E-mail (often several e-mail addresses) Network data storage A URL for a personal or business website, but Server-side technologies like scripting and database access may or may not be provided Available bandwidth (upload and download speeds may vary considerably) Cost will vary from one ISP to another Bottom line: Be sure to check out the options available and “shop around” before signing up

13. 13 Basic Tools A text editor for creating files A browser for displaying locally those files as they would appear on the web A file transfer program for uploading your files to your website on the server at your ISP “Gotchas” to Avoid Be sure to use a text editor, not a word processor, to create your files Don’t get wedded to a single browser, and always view your web pages in more than one Use a file transfer program that understands that end-of-line markers in text files are different on different platforms and deals with this “transparently” (most do so nowadays)

14. 14 Welcome to the Website of Nature's Source This is our first foray onto the World Wide Web. We are a small company dedicated to the health of our customers through natural remedies. We have a wide range of products that include: - books, and multimedia documents that help you get healthy and stay healthy - herbal medicines - equipment for injury free body toning exercises

15. 15 Once you have a file ready to go “online”, you need to place it in the correct location on your ISP’s server (your ISP will tell you where): One way: If you have created it on your PC, use a file transfer program to “upload” it to your ISP’s server – we will use WinSCP Another way: It may also be possible to create files directly on the server if you have an account there.