PageSpeed Module is a free, open-source plugin designed for WordPress that enhances website performance by optimizing page loading speed. Developed by Google, this module works with Apache and Nginx servers to minimize latency and reduce bandwidth usage. The core function of the plugin is to rewrite web pages efficiently, ensuring that users experience faster loading times, which can significantly improve user engagement and SEO rankings.

Additionally, the PageSpeed Module plugin enables users to purge caches created by either the Apache or Nginx modules, facilitating quicker updates and changes to the site. It also includes a development mode feature that allows developers to bypass the PageSpeed cache while working on the site. However, it's important to note that the plugin requires the PageSpeed Module to be installed on the server, as it will not function independently without it.