NETWORKING and the INTERNET The World WiDE WEb

What is Internet? INTERconnected NETworks Internet is a collection of local, regional, national and international computer networks that are linked together to exchange data and distribute processing tasks.

Why do people want to get connected to Internet? It provides freedom of communications Internet is termed by some people as the world of largest democracy with no government. The Internet is a rare example of a large democracy with no state of head, no official censors, no bosses, no board of directors. Nobody controls the Internet and in principle, any computer can speak to any other computer, as long as it obeys the technical rules of the TCP/IP protocol. This freedom of Internet helped it to move out of its original base in military and research institutions, into elementary and high schools, colleges, public libraries, and commercial sectors.

Communication in the Internet Protocol is a network term used to indicate the standard used by a network for communication. In a network, all machines must speak the same language to understand each other. We call this language as Protocol. For realizing a communication, both side must accept and apply the requested protocol.

Internet Protocol (IP) If you want to connect to another computer, transfer files to or from another computer, or send an e-mail message, you first need to know where the other computer is - you need the computer's "address." An IP (Internet Protocol) address is an identifier for a particular machine on a particular network; it is part of a scheme to identify computers on the Internet. IP addresses are also referred to as IP numbers and Internet addresses.

Uniformity of Protocol TCP (Transmission Control Protocol) / IP (Internet Protocol) TCP/IP is a family of protocols which contains more than one hundred information communication protocols.

Why is TCP/IP so important The Internet would never have expanded so rapidly without a commitment to Global Standardization. Its hard to get experts to agree on a single protocol. TCP/IP is very robust and allows for numerous levels of sub-networks.

What is an IP address A way to identify computers or machines on a network A unique identifier Used to connect to another computer All machines connected to the Internet agree to use the same scheme for establishing an address. Computers can not have the same IP addresses.

World Wide Web (WWW) It is also commonly known as ‘The Web’. Remember: There are companies that use the Internet to connect two computers, yet these computers are not part of the WWW.

URL examples mailto:ebreimer@siena.edu http://www.cs.siena.edu yahoo.com.ph emis.cec.edu.ph

Parts of a Web Address A web address is typically composed of four parts: For example, the address http://www.google.com.ph is made up of the following areas: http:// This Web server uses Hypertext Transfer Protocol (HTTP). This is the most common protocol on the Internet. www This site is on the World Wide Web. google The Web server and site owner/maintainer. com This site means it is a commercial type ph This tells us it is a site in Philippines.

Web Server Suffixes com (commercial) edu (educational institution) gov (government) net (network) org (organization) You might also see addresses that add a country code as the last part of the address such as: ph (Philippines) uk (United Kingdom) fr (France) us (United States of America) au (Australia)

Using Browsers Can type URLs HTML tags tell browser how to display web page data Back, forward and refresh buttons Setting a home page Print and copy options History list Favorites and bookmarks Edit and Find Infoweb: browser Lab: browsing and searching

HyperText Transfer Protocol Internet Protocol Standard HTTPS (Secure) creates a secure channel over an insecure network.  is a communications protocol for secure communication over a computer network,  The main motivation for HTTPS is to provide authentication of the visited website and prevent wiretapping and man-in-the-middle attacks. HTTPS URLs begin with "https://" and use port 443 by default, whereas HTTP URLs begin with "http://" and use port 80 by default. HTTP is insecure and is subject to man-in-the-middle and eavesdropping attacks, which can let attackers gain access to website accounts and sensitive information, and modify webpages to inject malware or advertisements. HTTPS is designed to withstand such attacks and is considered secure against such attacks.

Internet Terminology Backbone: defines main Internet routes Constructed and maintained by major telecommunications companies

Internet Terminology Packets: small chunks of data ready to travel the Internet Router: helps send along the packets to correct destination CD screentour: web sites provides files

Internet Service Provider (ISP) Provides internet access to businesses, organizations and individuals Provides telecommunications equipment User ID and password required Connects you to backbone E-mail account monthly fee Should have local access telephone numbers

Internet Service Provider - Networks

Digital Subscriber Line (DSL) originally digital subscriber loop) is a family of technologies that are used to provide internet access by transmitting digital data over telephone lines. In telecommunications marketing, the term DSL is widely understood to mean asymmetric digital subscriber line (ADSL), the most commonly installed DSL technology.

What is the difference of HTTP and TCP/IP? Questions What is the difference of HTTP and TCP/IP?