1. CS 101 – Dec. 2 Download speed Internet vs. Web Domains HTML

2. Measuring speed Overhead = prepare & assemble message Flight time = first bit to arrive at destination Bandwidth = max rate to propagate data (cruising speed) Total time = overhead + flight time + (msg size)/bandwidth

3. How much longer? FileSizeProgress“time left”rate #1815 KB65.1%3:081.5 KB/s #25.9 MB64.8%24:031.5 KB/s

4. Examples

5. Hypertext A text document that contains links to other documents. Also may contain “multimedia” Filename *.html Software: editor…browser.

6. Some terminology Internet = global “network of networks” Some Internet applications: –WWW = linked documents on the Internet –E-mail –chat –FTP = file transfer prototcol

7. Web terminology HTML = standard language for hypertext Web page = hypertext document (*.html) Web site = collection of pages & folders usually starting with index.html Web server = machine containing site Web browser = program that interprets HTML to show on screen

8. Web addressing Location of file is given by a Web address or URL. http://www.seds.org/billa/tnp/saturn.html saturn.html = page billa/tnp = folders www.seds.org = site [ server.place.domain]

9. Domains Three letter for U.S. (.com,.org,.net,.edu,.mil,.gov) Two letter for countries (.ca,.uk,.za,.ch,.de,.is, cn,.at,.us ………) Beware of exceptions Newer domains (.info,.museum,.biz, …)

10. Making Web pages Web pages written in HTML. 2 ways… Type in HTML code in text editor. –Enter “tags” as you go. Use “web generator” such as Dreamweaver –WYSIWYG

11. HTML format Web browsers read HTML files.... Head section is optional Body contains material to appear in browser window.

12. Minimal example The simplest Web page contains text. –Can format with various font commands … Hello!

13. Common tags h1, h2, etc. = headings br = line break p = paragraph ol, ul, li = used for lists hr = horizontal rule b, i = bold or italic sub, sup = subscript or superscript

14. Examples 7 th Who wrote Das Rheingold ? Gold Silver Bronze