When you localize a car you’re interested in only the car’s position and its movement. This is often called the State of the car. The state of any system is a set of values that we care about. In the cases you’ve been working with, the state of the car includes the car’s current position, X, and its velocity. In code this looks something like this. The State of the car gives us most of the information we need to form predictions about a car’s future location. And in this lesson we’ll see how to represent state and how it changes over time. For example, say that our world is a one-lane road and we know that the current position of our car is at the start of this road, at the zero meter mark. We also know the car’s velocity, it’s moving forward at a rate of 50 meters per second. These values are its initial state. What do you think the state of the car will be after three seconds elapse?