Authentication Overview
Depending on your setup, these options exist for requiring authentication for visitors to your site. A typical use case for this would be an intranet.

Site Authentication for your visitors on aem.live
The easiest way to set up an intranet

Site Authentication for your visitors on hlx.live
Setting up an Intranet on the previous architecture

Site Authentication for your visitors when using AEM Authoring
When you author using AEM Sites and Universal Editor, you also must enable it in your AEM environment.

Site Authentication with Cloudflare Zero Trust
Cloudflare Zero trust offers a powerful Identity Provider to be used with aem.live
Follow the instructions below to set up authentication for authors if you are using Sidekick and the Admin API. Setting up authentication is a requirement for enforcing user roles and permissions.

Authentication for your Authors
Authentication for Authors using Sidekick and the Admin API