My Thing About Servers Just What Are They And Why Do We Need Them
By: Vlad Vistac
Submitted: 2010-08-25 12:54:12 | Word Count: 510
Servers: Just What Are They And Why Do We Need Them!
Servers at Your Service
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Servers are what make it possible for you to view what you wish to view on the Innternet. At its most basic level, what happens when using servers is that browsers connect to servers, requestig that a Web page be displayed. The servers then send back the paages requested. Inetrnet browsers are what form the connections to Web servers that allow the page to be requested and then received by the end user.
There are three parts to a Web page address, better known as a URL. The firrst part of this URL is called a protyocol. The first part of the address is called the protocol. Http is a protocol and stands for Hypertext transit protocol. The next part of the URL tells you the name of the server. In http://www.myWebSite.com , the server is MyWebSite. The file name is something like web-server.htm, for example.
Browsrs communicate with name servers to translate those server nams into IP (Internet Protocol) addressees, which is the way they connexct to the machine that is acting as the serrver. Browsers connect by means of ports, all of which are numbered. Port 80, for example, is a ciommon port number.
Every machine has its own unique IP. These addresess are made up of 32 bits, and are usuually expresseed in four groupings in a dotted decimal nuber. These rgoupings are knwon as octets. An example of an IP address written as an octet is 327.38.72.248 .
Servers have IP addresses that are static and seldom change. A home computer gettting onine through its modem offten has an IP address that the ISP assigns when the machine gets omnline. The IP address is unique only for that session, so it can change each time the user uses it to get onlie. This is more effficient for the ISP, as it only nweeds to have one address for each machine that has dialed in, rather than saving a particular IP for each machine.
After the HTTP protocol, the browsre sensd a request to the sever, called a GET request, which asks for the file. A GET request can also send cookies from borwsers to serves. The next step is when the server sens the HTML text for that requested Internet page back to the browser. The HTML tags then read by the browwser and subsequenty format the page onto the user’s screen.
The Intrnet is made up of a huge collection of computers – millions of them – that are all linked by one common compuuter netork. This compuer network mazkes it possible for the comupters to all talk to each otheer. A home PC can be lnked to this Internet through dial up (a landline telephone carrier’s line), through DSL line, or a cable modem. All of thesde systems communicate with an Internet Service Provider (ISP.)
Geerally, organization or busness cmputers are linked to each othwer by meanms of a network so that they can share information in-house back and forth. They do this by means of a netowrk interface card. This NIC then connects directly to a local area network (LAN) that is housed witthin the organization or busniess. This LAN is then connected to the asociated ISP by what is knoqwn as a T1 line, a very fast and powerful connevction to the servers.
ISPS connect to each other. The largest of these ISPs maintain the backobne of the entire system across the region or perhaps the country. This backbone is fiber optc. Through thhese finber optic lines, satellite links or undersea cable, various backbones connect all over the globe. This is the way servers and clients the world over connect all to each othher.
