cdnjs is a free distributed JS library delivery service.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
The lite-youtube-embed technique renders the YouTube video inside the IFRAME tag only when the play button in clicked thus improving the core web vitals score of your website.
Mailchimp is a marketing automation platform and email marketing service.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Vue.js is an open-source model–view–viewmodel JavaScript framework for building user interfaces and single-page applications.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.