.:This page is being edited by Eddie Loeffen:.

THE WWW


  • This page looks at The world wide web from a technology perspective. It will cover web servers, browsers, routers, IP addresses and DNS

Web servers


  • A web server is a computer running special software and connected to the internet. It's job is to deliver (serve up) webpages from a website on request.
  • Each web server has an IP address and a domain name. The domain name will be something such as www.wikispaces.com. If the user wanted the page called index.htm, they would type www.wikispaces.com/index.htm. This would tell the browser to visit the server with the domain www.wikispaces.com, and ask it for the page index.htm, which the server would then send to the browser for the user to see.


Browsers


  • A browser is a piece of software that connects to the internet and displays webpages from a website on a webserver. The user inputs a desired domain and page name (www.wikispaces.com/index.htm) and the browser will go to that domain that the web server is located at and ask for that page. The page is then sent to the browser and the user can view it.

  • Well known browsers (in order of popularity at August 2006 See Reference: 1) include:




Routers


  • A router is a machine that sends data packets through networks. A router is connected to two or more networks, which are usually two LANs (Local Area Networks) or WANs (Wide Area Networks) or a LAN and its ISP's (Internet Service Provider's) network. Routers are located where two or more networks connect, called a gateway, and are the critical device that keeps data flowing between networks and keeps the networks connected to the Internet. When data is sent between locations on one network or from one network to a second network the data is always seen and directed to the correct location by the router. They accomplish this by using headers and forwarding tables to determine the best path for forwarding the data packets, and they use protocols such as ICMP to communicate with each other and configure the best path between any two hosts.

  • external image router.jpg
  • This image shows the flow of data to multiple computers sharing one high speed Internet connection. (See Reference: 3)




IP Addresses


  • An IP Address is an identifier for a computer or device on a TCP/IP network. An IP Address is formatted with 4 numbers ranging from 0 to 255, each number separated by a period (.). For example, 1.160.10.240 could be an IP address.

  • Within an isolated network, you can assign IP addresses at random as long as each one is unique. However, connecting a private network to the Internet requires registered IP addresses to avoid duplicates.

  • ipconfig.PNG
  • Using command prompt and the command "ipconfig" to find your IP address (Addresses blacked out).


DNS


  • DNS stands for Domain Name System (or Service or Server) and is an Internet service that translates domain names into IP addresses. We use domain names because they are much easier to remember. The Internet however, is actually based on IP addresses. Every time you use a domain name, a DNS must translate the domain into the correct IP address. For example, the domain name www.example.com might translate to 198.105.232.4.



Bibliography




- Eddie_Loeffen Eddie_Loeffen Dec 31, 1969