The quantities which have only magnitude but no direction is called scalar quantities.
It is specified completely by a single number along with a proper unit.
Example:- Temperature, mass, length, time, work etc.
These are the physical quantities which have both magnitudes and directions and obey the triangle or parallelogram laws of addition and subtraction.
It is specified by giving it’s magnitude by a number and its direction.
Example:- Displacement, acceleration, velocity, Momentum, force etc.
It is represented by bold Face type and also by an arrow placed over a letter.