WebServer!
A
web server is a computer program that delivers (serves) content, such as this web page, using the Hypertext Transfer Protocol. The term web server can also refer to the computer or virtual machine running the program.
There are several requirements for a Server computer - it needs to be
fast, have a large storage capacity hard disk and lots of RAM. But the
most important is having a permanent internet address also known as an
I.P. (Internet protocol) address. If the I.P. address changes, the web
site would not be found and will appear
offline - the browser will display a
cannot find web site kind of error.
The more powerful the server, the faster it can serve up
website pages. Slower, smaller servers may result in frustrating lag time for
viewers. High traffic can also slow servers that are not powerful enough to
handle high volumes of data exchange. This lag time should be a concern if you
are shopping for a web host. Most web hosts have a page dedicated to sharing
technical information about their web server, including speed, capacity, network
configuration and other details.
The primary function of a web server is to deliver web pages (HTML documents) and its content (e.g. images, style sheets, JavaScripts) to clients. A client, commonly a web browser makes a request for a specific resource using HTTP and, if all goes well, the server responds with the content of that resource. The resource is typically a real file on the server's secondary memory, but this is not necessarily the case and depends on how the web server is implemented.
While serve content, a full implementation of HTTP also includes a way of receiving content from clients. This feature is used for submitting web forms, including uploading of files.
Many web servers also support server-side scripting (e.g. ASP, PHP,JSP,COLDFUSION). This means that the behaviour of the web server can be scripted in separate files, while the actual server software remains unchanged. Usually, this functionality is used to create HTML documents on-the-fly as opposed to return fixed documents. This is referred to as dynamic and static content respectively. The former is primarily used for retrieving and/or inserting information to databases. The latter is, however, typically much faster.
History of web servers
In 1989 Tim Berners-Lee proposed to develope a new project, which had to exchange of information between scientists by using a hypertext system. As a result of the implementation of this project, in 1990 Berners-Lee wrote two programs:
a browser called WorldWideWeb;
the world's first web server, later known as CERN httpd, which ran on NeXTSTEP.
Between 1991 and 1994 the simplicity and effectiveness of early technologies used to surf and exchange data through the World Wide Web helped to port them to many different operating systems and spread their use among lots of different social groups of people, first in scientific organizations, then in universities and finally in industry.
In 1994 Tim Berners-Lee decided to constitute the World Wide Web Consortium to regulate the further development of the many technologies involved (HTTP, HTML, etc.) through a standardization process.
