Week-6 (Lecture-1) Publishing and Browsing the Web: Publishing: 1. upload the following items on the web Google documents Spreadsheets Presentations drawings 2. after publishing we get a URL (universal resource locator) of a unique page.

Week-6 (Lecture-1) What is required to publish? There are two ways to publish A unique domain name: Each domain name is registered with a DNS (Domain Name Server), which identifies a domain name with a unique Internet Protocol (IP) address. Web Space: Each website must have a web space allocated to it. This is provided by a web server, many of which are maintained by private companies.

Week-6 (Lecture-1) Domain names: Used to identify one or more IP addresses Ex. domain name microsoft.com represents about a dozen IP addresses. Domain names are used in URLs to identify particular Web pages Ex. in the URL the domain name is pcwebopedia.com. Domain name suffix: 1..gov - Government agencies 2..edu - Educational institutions 3..org - Organizations (nonprofit) 4..mil - Military 5..com - commercial business 6..net - Network organizations 7..sa – Saudi Arabia 8.th - Thailand

Week-6 (Lecture-1) Aspects of Domain names: Internet is based on IP addresses, not domain names Every Web server requires a Domain Name System (DNS) server DNS translate domain names into IP addresses. Internet Address: uniquely identifies a node on the Internet. name or IP of a Web site It can be URL (Universal resource Locator)

Week-6 (Lecture-1) IP address: 32 bit number assign to n/w device. It uses TCP/IP protocols. Sender knows the IP address before sending any packet. Its of two types IPv4 (home Use) and IPv6 (Big Organizations). 32- bit address use for represent 8 bit decimal no. separated by zero (0). I.e represent Range from to to

Week-6 (Lecture-1) DNS: translates Internet domain and host names to IP addresses. automatically converts the names we type in our Web browser address bar to the IP addresses of Web servers hosting those sites. DNS implements a distributed database to store this name and address DNS assumes IP addresses do not change (are statically assigned rather than dynamically assigned). Subnet mask: Another 32 bit no. Acts like a filter when applied on 32-bit IP address. By use of subnet mask system can determine which portion of IP address.

Week-6 (Lecture-2) What is World Wide Web (WWW)? Global interactive, dynamic, cross platform Graphical hypertext information system that runs on the Internet. Web Browser: Special software to show web page Ex. Internet Explorer, Mozilla Firefox Web pages available on the web server and show on client.

Week-6 (Lecture-2) URL: address of a specific Web site or file on the Internet uses forward slashes ( / ) to denote different directories Ex. ftp://info.apple.co/ Web Page: Single document written in HTML ( Hypertext Markup Language ) Includes the text of the document, its structure, any links Ex. documents and graphic images and other media.

Week-6 (Lecture-2) Home page: The first page of a website Automatically listed on the server It has all the main features and important Hyperlinks of that website. Search Engine: A software system Designed to search for information Search information may be the Web pages, images etc. It works on an algorithm or web crawler Ex. Archie, Gopher

Week-6 (Lecture-2) How search Engine Works? Ans. A search engine main 3 processes 1. Web crawling Search by Web crawling from site to site by spider in systematic way. 2. Indexing Collect, parses and store data for fast information retrieval Ex. Meta search engines

Week-6 (Lecture-2) 3. Searching: Use a search query to search. Three types of web query 1.Informational queries 2.navigational queries 3.Transactional queries Most popular search engines: Google search Bing Yahoo Search Ask AoI Search