|b-a| or | a-b | or | x |. Absolute value is the distance from a point corresponding to a number on the exponential axis to the origin, which is represented by "||". |b-a| or |a-b| represents the distance between the point representing a and the point representing b on the number axis. In mathematics, the absolute value or the modulus |x| is non-negative, regardless of its sign, that is |x|=x means positive x, |x|=-x means negative x (in this case -x is positive), and |0|=0.