cdnjs is a free distributed JS library delivery service.
Facebook pixel is an analytics tool that allows you to measure the effectiveness of your advertising.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
ASP.NET is an open-source, server-side web-application framework designed for web development to produce dynamic web pages.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.