Information on the Internet http hypertext transfer protocol

Information on the Internet

http • hypertext transfer protocol • Web clients (browsers) make request to the web server. • Looks for web page written in HTML.

URL • Uniform Resource Locator • Entire location of a page/image: • http: //www. amazon. com http: //keep 3. sjfc. edu/faculty/jsarachan http: //www. amazon. com/exec/obidos/searchhandle-form/102 -3711441 -9976104 http: //www. sjfc. edu/admissions/academics. asp http: //www. hammersaw. com/logo. gif

Parts of a Domain Name • Top Level (TLD). com, . edu, . net, . gov, . org, . biz, . info. ca, . uk, . tv • Second Level • Third Level (www)

IP Address/ Domain Name System • IP Address has 4 parts: 64. 236. 16. 20 • D omain name system links URL to IP address via DNS servers • DNS=Domain Name System • Static vs. Dynamic IP addresses

How Search Engines Work I • A search engine uses a form of software that can travel on the web called a “crawler” or “spider” or “bot. ” • Examines each page, and each link (some ignore images, pdf files, etc. ). • Information about each page (everything or headings, keywords) are sent back to database. • Webmasters can submit site to speed up process.

How Search Engines Work II • User submits keywords that match keywords from the site, as well as dates created or other criteria. • Information from database is returned, ordered by different rules (relevance, age). • User may be given title and URL and/or sentences about document (meta tags).

Optimization of Web Sites • Web Designers should pick obvious names for the URL—without hypens or misspellings. • Use meta tags. • Frequency of keywords on page.

Finding Web Sites • Use different rules (algorithms) to organize web pages. • Keyword frequency/placement/prominence • Fuzzy search • Relevance (order of keywords matter) • Site popularity • Paying for Placement • Boolean logic

Two type of search sites • Directories (indexes) • Search Engines

Google • http: //www. google. com • Works as phone book: combination of first and last name, city, state OR phone number • Finds street maps via yahoo or mapquest • Dictionary definitions • Stock quotes (to yahoo)

Typical Rules • • “spider man“ (include whole phrase) Spider -man (don’t include this word) Spider ANDNOT man(don’t include second word) (spider man) (one word or the other) Spider OR man (one word or the other) +spider +man (both spider and man) Spider AND man (both spider and man)

Searching Extras Google • biology site: www. sjfc. edu • link: www. sjfc. edu • Info: www. sjfc. edu • Advanced Search (and tips) in Google

Other search engines • • www. yahoo. com www. findarticles. com www. dogpile. com www. askjeeves. com www. beaucoup. com (free information) www. kartoo. com www. archive. org

Things You Can Find on the Internet • • • Websites Images MP 3 files News Maps/directions (www. mapquest. com) People(www. switchboard. com, whitepages. com, yahoo. com) Games (www. gamespot. com) Film or TV show information (www. imdb. com) Music Information (www. allmusic. com) Lyrics (type into Google) Health Information (www. webmd. com)

Bookmarks • Also called Favorites • In IE, if you are on a page you want to keep, choose: “Add Page to Favorites” • You can organize favorites and add URLs to toolbar.