I'm learning tf2 and i think i understand the aplications, which serves for measuring translation and rotation values for frame transform. But most videos explaining examples of it shows a mobile robot that knows where they are, simply saying that the tf takes care of that. Until now, i thought odometry was essential to get the robot position. I get it for simulations, because we only have to subscribe to some topic that displays the robot's pose, so we don't need to make our odometry, but for real robots, how is tf2 capable of that?