Wonderful! Whether the figure is moving forward or backward, it is travelling only along one line. In the other cases, it is not travelling on a single straight line.
The simplest quantity that captures whether an object is moving or not is its speed. For example, if Johnny is riding his bike at 80 km/h, it means that, if he continued at that speed, he will cover 80 km in 1 hour.

If an object's speed is \(0\), it is not moving. If an object's speed is not \(0\), it is moving. It's that simple!