Remote access through relay server

I noticed that there are two ways of connecting MCM from outside, one is port forwarding, which is pretty straight forward. The other one is through relay server. I am wondering whether WD has a server farm just for us to connect our MCM boxes at home? Or am I understanding it wrong? Thanks!

Yep, you’re understanding correctly. If it’s using RELAY, you’re connected via a secure VPN tunnel that your My Cloud establishes to WD’s servers.