Yes that is my understanding. 3 machines per license.
Yes, for a single user license, the software may be installed on up to three computers but it may only be used on one computer at a time and only by the same individual.
So you can have it simultaneously activated on up to three computers (e.g. in three different locations), but only use one installation at the same time. No need to deactivate it if you are going to use it on one of the other computers, and it's a perpetual single-user license that doesn't expire. Only during activation an internet connection is required, which helps when working in a remote location with limited internet connection (one can activate in one location with an internet connection, and take the computer to another location or on a travel without connection).
Cheers,
Bart