A Web server is an application that uses the client, server model and the World Wide Web’s ( HTTP ), to serve the files that form web pages to the web users. There are some web servers which are used in the web hosting industry, however, from all of those web servers, commonly used are :
1. Linux (Apache).
2. Windows (Internet Information System) .
The user requests a page by typing a URL i.e. a domain in a browser, and the web server receives the request. The web server looks at the file extension to determine whether a web application server must process the page. Then, one of the following actions occur:
1. If the user requests a file that is a simple web page (often one with an HTML extension), the web server fulfills the request and sends the file to the browser. The file is fetched from the hosting package which can anything from a shared hosting package to a dedicated server hosting. The hosting package actually depends on the website and many other factors.
2. If the user requests a file that is a page that a web application server must process (one with a CFM, CFML, or CFC extension for Cold Fusion requests), the web server passes the request to the web application server which again can be a simple hosting package or a dedicated server hosting. The web application server processes the page ( the requested one ) and sends the results to the web server, which returns those results to the browser. The following figure shows the entire process:
Because web application shared hosting packages or dedicated servers interpret programming instructions and generate output that a web browser can interpret, they let web developers build highly interactive and data-rich websites, which can do tasks such as the following:
* Query other database applications for data.
* Dynamically populate form elements.
* Dynamically generate Flash application data.
* Provide application security.
* Integrate with other systems using standard protocols such as HTTP, FTP, POP, and SMTP.
* Create shopping carts and e-commerce websites.
* Respond with an e-mail message immediately after a user submits a form.
* Return the results of keyword searches.
TCP port 80 is always used to http:// request.
This entire process is followed no matter the site is hosted on a shared hosting package which are also hosted on dedicated servers or the client actually has a dedicated web hosting. Though, the process may vary depending on the hosting package or the dedicated server hosting the client has, however, the basic concept is the same in order to make sure that the website resolves perfectly and the requested page is sent to the browser of the requester.