Which monitor?
48-144 is a larger range, so that means it can control the refresh rate of the monitor to those points. Below 48/60 it will behave differently. With classic freesync I think that meant nothing, but Premium I think can do frame doubling at least. No tearing, but latency goes up since the same frame gets displayed multiple times.
"With LFC, if your game’s frame rate drops below the monitor’s lowest supported refresh rate, frames automatically display multiple times. This means you’ll stay in your monitor’s supported refresh rate range and, therefore, maintain smooth gameplay. "
Above 144 FPS, I believe VRR and V-Sync would need to be off for it to go above that, and that would involve tearing, but minimal latency.
https://www.tomshardware.com/reviews/amd-freesync-monitor-glossary-definition-explained,6009.html