Velocity Is A Vector:

Since velocity has both direction and magnitude components, it is a vector quantity. You cannot express velocity without defining both these components. In the illustration of a car driving along a highway from one town to the other, its speed may be constant, though the velocity changes however. If you are moving along at 25 m/s and then you come to a bend in the road, your velocity changes as your direction changes.

Vectors can be demonstrated graphically as line segments with arrowheads. The speed part of a velocity vector is represented by the length of the line segment, and the direction is symbolized by the orientation of the arrow. In the figure shown below, three velocity vectors are shown for a car traveling along a curving road. Three points are shown, called A, B, & C. The corresponding vectors are a, b, & c. Both the direction and speed of the car change with time.