For licensing/cost purposes, Gurobi always aims to count physical cores. To this end, it queries the operating system for the number of physical and logical cores.
Gurobi licenses always contain the (maximal) number of (physical) cores for which they are valid. (For reasons of backward-compatibility, they also contain the number of sockets if it is greater than 1.)
On Virtual Machines
On virtual machines, the number of physical cores is more difficult to obtain since VMs typically hide the difference between physical and logical cores.
In a properly configured VM with hyper-threading, a total number of 16 logical cores would be counted as 8 physical cores. It is always possible to download and install Gurobi and use the "grbprobe" utility to check how many physical cores are measured by Gurobi.
On AWS and Azure
AWS and Azure machine specifications in the Cloud Manager show the number of physical cores.
All machines that we tested on AWS show physical cores being half the number of logical cores. However, there are some machines on Azure where hyper-threading is turned off, and we can see physical cores being equal to logical cores.