Vector A physical quantity which has direction in addition to its magnitude. For example force is a vector quantity because it acts at a particular direction. Similarly, displacement, velocity, momentum, acceleration, electric and magnetic field etc. are all vector quantities.

A vector in a figure is represented by an arrow. The magnitude of the vector is determined by the length of the arrow, using an appropriate unit. In text a vector is denoted by a bold faced letter or a letter with an arrow sign on top (A). The magnitude of A is denoted by A or ½ A½ .