Scalars and vector quantities are two types of physical quantities used to describe various properties and phenomena in physics.   A scalar quantity is a physical quantity that has magnitude (size) only, without any specific direction. Scalars are characterized by a numerical value and a unit of measurement. Examples of scalar quantities include mass, temperature, time, speed, and energy. When performing mathematical operations with scalar quantities, you can simply add or subtract their numerical values.   A vector quantity, on the other hand, is a physical quantity that has both magnitude and direction. Vectors are represented by arrows, where the length of the arrow represents the magnitude of the vector, and the direction of the arrow represents the direction of the vector. Examples of vector quantities include displacement, velocity, acceleration, force, and momentum. When performing mathematical operations with vector quantities, you need to consider both magnitude and direction. Vector addition involves both adding the magnitudes of the vectors and considering their directions.   In summary, scalar quantities are described by magnitude only, while vector quantities have both magnitude and direction. Scalars are added or subtracted by their numerical values, while vectors require consideration of both magnitude and direction in mathematical operation