When you walk from a point A to a point B along a line A B ¯ ¯ (without changing directions) your net displacement and total distance covered are both equal to the length of said line A B . If you then return to point A (without changing directions) then your net displacement is zero while your total distance covered is 2 A B . This example captures the essential idea behind the inexact differential in one dimension. Note that if we allowed ourselves to change directions, then we could take a step forward and then backward at any point in time in going from A to B and in-so-doing increase the overall distance covered to an arbitrarily large number while keeping the net displacement constant.