The answer depends on the licensing model you’re using:
- When connected to ArcGIS Online or ArcGIS Enterprise with a Named User account, you can log in on up to three machines at the same time. If you’re disconnected and have your license set to work offline, you can work with the one machine that has been taken offline.
- One Single Use license can be used to authorize one machine.
- Concurrent Use licenses allow authorization of one machine per license.