According to Microsoft, Active Directory Certificate Services (AD CS) is a “Server Role that allows you to build a public key infrastructure (PKI) and provide public key cryptography, digital certificates, and digital signature capabilities for your organization.”
What this means for me, is the server becomes a Certificate Authority on the domain and can issue digital certificates. I can then assign a certificate to my intranet web app, allowing it to use HTTPS - one of the requirements needed before it can become a PWA.
Here are the screenshots of the steps taken to add the AD CS role.
