If you are using the Game of Thrones, Silmarillion or Middle Earth datasets and switch to map mode you’ll see that there are save and load buttons.
The idea here is that you might want to emulate a fantasy journey in the real world. It’s a way of mapping a real world journey to something that might have happened in a story so that you have a better appreciation of the distance involved.
For example, you may want to do a sponsored bike ride from Hobbiton to Rivendell, or maybe you’re going to walk to Mordor. If you set the journey up in the normal way with start and end locations and then save it, when you load it again it will show a red marker so that you can see how your location has changed relative to the stored journey.
That way you can keep track of your progress, so you may be in the middle of nowhere in the real world, but you know exactly where you are in the fantasy world, you just can’t see it. That’s what imagination is for.