Do you need user CALs for each server?

For each user or device

A server software license by itself doesn’t provide the license rights to allow anyone to connect to that computer, whether they work for the company or not. Instead, each user or device needs a CAL.

How many Microsoft CALs do I need?

Any user or device that accesses Microsoft server software directly or indirectly legally requires at least one CAL, Microsoft officials say. There are a number of different types of CALs: Device CALs, User CALs, Base and Additive CALs, Premium CALs, Enterprise CALs and more.