Loading a web page involves multiple requests for various files from the server
When a user loads a web page in a web browser, a sequence of HTTP requests are made to the server for the various files necessary to display the web page properly in the browser.
For example, let’s say a user loads this site, http://wd.onepotcooking.com/. Here is a set of steps that may be triggered as a result of a simple action such as this:
- Typing that URL in the address bar and clicking “go” causes the browser to make an HTTP request to the wd.onepotcooking.com server for the default web page at that address.
- The server finds the file on its hard drive that contains the default HTML code for the requested page of the site, and sends that code to the browser as part of its HTTP response to the browser’s initial request.
- The web browser then may automatically send another request for the default favicon file that goes along with the requested website. The favicon file is the little image that sometimes shows up next to the address in the web browser.
- The server will try to find the favicon file that goes along with the requested web page on its hard drive, and if such a file exists, it will send the contents of that file back to the browser as part of its HTTP response.
- The web browser will eventually start analyzing the HTML code it received back from the server in response to its first request. The HTML code may indicate to the browser that there are other files necessary in order to display the requested web page properly in the browser. These might include CSS files that contain style and design information about the page, Javascript files that define interactive behaviors that should happen on the page, image files that are used for graphics or photos on the page, and other file types such as Flash animations, Java applets, and a variety of other more obscure types of content that may show up on some web pages.
- The web browser will go through this list of files and request them one-by-one from the web server using the same HTTP request/response mechanism until all files that are necessary to display the web page properly have been received from the web server.
- Finally, the web page shows up nicely in the web browser and the user is happy.
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