Apache is a free and open-source cross-platform web server software.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Linkedin Ads is a paid marketing tool that offers access to Linkedin social networks through various sponsored posts and other methods.
Open Graph is a protocol that is used to integrate any web page into the social graph.
W3 Total Cache (W3TC) improves the SEO and increases website performance and reducing load times by leveraging features like content delivery network (CDN) integration and the latest best practices.