The object in motion, indicated by the heavy circle at the left side of the image, is undergoing motion with negative acceleration. This means that the velocity of the object is decreasing(strictly speaking, becoming more negative). The short line coming off of the top of the object represents the velocity of the object, and is decreasing in length as the object slows down, before pointing downwards (negative direction) as the object changes direction. The object starts off with an initial positive position and velocity. The first graph depicts the object's position as a function of time, in this case it is increasing at an decreasing rate (the "rate of increase of position" is the velocity) before decreasing when the velocity becomes negative. The second graph depicts the object's velocity as a function of time, in this case the velocity is decreasing at a constant rate (the "rate of increase of velocity" equals acceleration which is negative) becoming negative after sufficient time has passed.

The "turn around" point of the object's trajectory has some interesting characteristics. It is the point of maximum displacement, and occurs at the instant in time when the speed is zero (but note, it is only zero for this instant). The motion illustrated is analogous to throwing an object up in the air; the maximum height is the turnaround point.