Understanding dimensions is of utmost importance as it helps us in studying the nature of physical quantities mathematically. The basic concept of dimensions is that we can add or subtract only those quantities which have same dimensions. Also, two physical quantities are equal if they have same dimensions.
Dimensions help understand how physical amounts are related to their dependence on basic or fundamental volumes, i.e. how the body's dimensions rely on mass, time, length and temperature.
When discussing Newton's laws of motion, particularly Newton's third law of motion, the terms that almost everyone will use are "action" and "reaction".
You must not take this to mean that they understand what they're talking about.
