Apache is a free and open-source cross-platform web server software.
Header Footer Code Manager by Draftpress is a easy interface to add snippets to the header or footer or above or below the content of your page.
Google AdSense is a program run by Google through which website publishers serve advertisements that are targeted to the site content and audience.
Open Graph is a protocol that is used to integrate any web page into the social graph.
PHP is a general-purpose scripting language used for web development.
Priority Hints exposes a mechanism for developers to signal a relative priority for browsers to consider when fetching resources.
WordPress is a free and open-source content management system written in PHP and paired with a MySQL or MariaDB database. Features include a plugin architecture and a template system.
Yoast SEO is a search engine optimisation plugin for WordPress and other platforms.