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.
Google Analytics is a free web analytics service that tracks and reports website traffic.
Google Sign-In is a secure authentication system that reduces the burden of login for users, by enabling them to sign in with their Google account.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Imgix is a visual media platform for managing, processing, rendering, optimising and delivering your existing images.
Lodash is a JavaScript library which provides utility functions for common programming tasks using the functional programming paradigm.
Open Graph is a protocol that is used to integrate any web page into the social graph.