What is the difference between scalar and vector quantities?

This is a classic exam question! The difference is all about direction.

A Scalar quantity has only magnitude (size) but no direction. For example, if I ask "How much rice did you buy?", you say "5kg". You don't say "5kg to the North". Mass, Time, and Temperature are scalars.

A Vector quantity has both magnitude AND direction. For example, if you are directing a stranger to the market, you can't just say "Walk 500 meters." You must say "Walk 500 meters forward". Displacement, Velocity, and Force are vectors because the direction matters as much as the amount.