HTTPS stands for Hypertext Transfer Protocol Secure, it works in conjunction with a ssl certificate to provide websites users encryption on thier browsing. It must be noted however that not all sl certificates offer the same degre of protection. As for you question depending on your website design you dont want you website calling on any absolute url paths with a http in it also you want to redirect all these requests from your html to https and also those coming in from a browser this is where you use a redirect to force the https