Here's one example: https://www.google.com/about/datacenters/locations/st-ghisla... In this case, they pull grey water (like the water you get from a clothes washing machine) from a nearby source, pump the water past the server's hot parts, and the water evaporates, absorbing heat in the process (https://en.wikipedia.org/wiki/Enthalpy_of_vaporization).

Alternatively, you can cycle closed-loop water through a chiller to a hot server and back, or just cool the air around the server (CRACs and CRAHs) using either water or refrigerant as the heat-carrying material.