Its basically a computer controlled system....when the system detects the trailer beginning to sway, the computer directs individual brakeing to selected wheels to slow/stop the sway.
I had it on my previous 2021 Ranger and my 2019 current Expy has it. When towing our travel trailer I have not used it as my set up includes a weight distributing hitch with a sway control. If in doubt, depending on your hitch set up, you may want to engage it especially if your towing a trailer with just a hitch ball without a weight distributing set up.