`node["apache"]["mod_php5"]["windows"]["source"]` specifies the URL at which a zip file of PHP can be downloaded. And `node["apache"]["mod_php5"]["windows"]["file"]` specifies the path of the dll within the extracted folder. It is possible that the dll is not in the top level folder. And, going along with the Chef convention that everything should use forward slashes as long as possible, the path will only ever contain forward slashes.