A scalar quantity is one which has only magnitude, while a vector quantity is one which has magnitude as well as direction.
That is, a scalar quantity can be understood just by a number, say 5 kg sugar. Here, to buy sugar you only need a quantity known as mass, i.e. 5 kg is the only information that is needed to buy sugar.
On the other hand if one needs to go to school, you would need the distance that you have to walk as well as the direction in which you need to walk.
Examples of scalar quantities: Mass, time, distance, speed, etc.
Examples of vector quantities: Weight, displacement, velocity, acceleration, etc.