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In two-dimensions, we can describe the velocity vector like this.One is to specify the speed of the body along the x-axis (the x component, vx) and the speed of the body along the y-axis (its y-component, vy).Alternately, a two-dimensional vector can be specified completely by stating its speed v (i.e., the magnitude of the velocity vector) and its direction as an angle q.The velocity vector and its components form a right triangle.

We can describe the velocity vector by three components in three dimensional motion as vx,vy and vz. The quantity vx tells one how fast the body is moving in the x-direction independent of how fast it may be moving in the other directions. If the x-axis is associated with the due East, then vx tells how fast the body is moving to the East.Likewise, vy, tells how fast the body is moving in the y-direction independent of the other two directions, and likewise vz tells the body's speed along the z-direction.