Webservers

A webserver’s main focus is handling requests from browsers. As described earlier, a browser may request a document, post data, or perform an AJAX request to get data. The webserver uses HTTP headers as well as a URL to determine what action to take. This is where things get very different, depending on the webserver, configuration, and technologies used.

Most out-of-the-box webservers such as Apache and IIS are made to serve static files such as .html, .css, and media files. To handle POST requests that modify server data and AJAX requests to interact with backend services, webservers need to be extended with server-side scripts.

A server-side script is really anything that a webserver can execute in order to perform the task the browser is requesting. These scripts can be written in PHP, Python, C, C++, C#, Perl, Java, ... the list goes on and on. Webservers such as Apache and IIS provide mechanisms to include server-side scripts and then wire them up to specific URL locations requested by the browser. This is where having a solid webserver framework can make a big difference. It often takes quite a bit of configuration to enable various scripting languages and wire up the server-side scripts so that the webserver can route the appropriate requests to the appropriate scripts.

Server-side scripts either generate a response directly by executing their code or connect with other backend servers such as databases to obtain the necessary information and then use that information to build and send the appropriate responses.