Your vehicle's towing capacity is a specification you can find in the owner’s manual. Or you on the manufacturer’s website. Make sure you know the exact model and year it was manufactured.
The "Unbraked Towing Capacity" is the maximum weight allowed for a trailer without brakes. These are typically small box trailers. "Braked Towing Capacity" is for heavy trailers, usually over 740kgs, that have their own brakes..
The main types of trailer braking systems are “hydraulic surge bakes” found on boat trailers and rented car trailers. These are activated when the car slows and the trailer pushes into the hitch. Electric brakes are controlled by a wire signal from the tow vehicle. It can be precisely controlled by the driver if the tow bar electrics are well set up with a brake controller.
The other towing capacity figure to note is the Gross Combined Weight Rating (GCWR). This is the maximum weight of your vehicle with a trailer attached, as determined by the vehicle manufacturer. This includes passengers and luggage loads.
It's worth taking your fully loaded car and trailer to a weigh bridge to check the combined weight. This will ensure you're towing legally and safely. If it's over the allowable weight, consider getting a Gross Vehicle Mass (GVM) upgrade for your vehicle.