Scalar Quantities:

The physical quantities, which have magnitude but no direction are called scalars, accompanied by a unit.
Mass, length, distance covered, time, density, work, temperature, charge, specific heat, energy, power, speed, length, etc. are few examples of scalars,

A scalar quantity can be completely described by a number; representing its magnitude. A scalar may be positive or negative. They can be added, subtracted, multiplied and divided according to the simple rules of Algebra.

Vector Quantities: The Physical quantities which have both magnitude and direction are called vectors.
Displacement, velocity, acceleration, force, momentum, electric field, impulse, gravitational field etc. are few examples of vector quantities.

It may be pointed out that the vectors can not be added, subtracted, multiplied or divided as one may do in case of scalars. It is because, in addition to magnitude, vectors have direction also. Vectors are added, subtracted and multiplied according to the rules of Vector Algebra. The division of a vector by another vector is not a valid operation in Vector Algebra.