The first step in solving a problem is to set up a coordinate system. We'll also need to distinguish between scalars and vectors. A scalar is something that has only a magnitude, like area or temperature, while a vector has both a magnitude and a direction, like displacement or velocity. In analyzing the motion of objects, there are four basic parameters to keep track of. These are time, displacement, velocity, and acceleration.
Time is a scalar, while the other three are vectors.
The difference will be more obvious in 2 dimensions. The displacement represents the distance traveled, but it is a vector, so it also gives the direction. If you start in a particular spot and then move north 5 meters from where you started, your displacement is 5 m north. If you then turn around and go back, with a displacement of 5 m south, you would have traveled a total distance of 10 m, but your net displacement is zero, because you're back where you started. There are several ways to analyze those 90 seconds between the time you left home and the time you arrived back again.