PHP Architecture Overview

The job of a web server (such as Apache or Microsoft's IIS) is to reply to requests coming from a client (usually a web browser). When a browser connects to a web server, it requests information by sending a URL (Uniform Resource Locator). For example, if you browse to the URL, your web browser connects to the server at and requests a file named software.html.

After the web server has received this request, it must decide how to reply. If the requested file cannot be found, you'll see the all too familiar HTTP 404 - File not found. Most web servers will choose a response based on the extension of the requested file. A filename ending with .html (or .htm) is usually ...

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