Latching is where, via the driver information center (DIC), you select any feature you want, and that feature stays selected, even if you change the DMS, until you choose to go back info the DIC, and change it. For example, if you latch the exhaust into it's loudest setting, even if your turn the car off or on, the exhaust will always stay in its the loudest exhaust setting -- until you back into the DMS and tell the car to revert the exhaust system to its being automatically connected to the DMS again. -- as it comes from the factory. This is true of every latchable component, e.g., steering sensitivity, shock firmness settings, etc., etc.
There are two exceptions to this. First if you totally run down the battery, the car will revert to its factory settings. Second if you temporarily set the traction management controls into a "less safe mode" when you are tracking your car, such as choosing to turn off traction control, the car will not keep those "less stable" stability systems when you turn the car off. This is to prevent someone else, perhaps the next morning, grabbing the same key fob, with that person not knowing those traction control systems have been turned off, from getting into trouble.