Final answer:
The absolute value of a number is its distance from 0 on a number line, and it is always non-negative.
Step-by-step explanation:
The best definition of absolute value is a number's distance from 0 when plotted on a number line. This definition illustrates that the absolute value is always a non-negative value, regardless of whether the original number is positive or negative. For example, the absolute value of -4 is 4, and the absolute value of +4 is also 4, since both points are 4 units away from 0 on the number line.
It is important to note that the absolute value of a number does not involve any change in the number itself—it only considers the magnitude. Therefore, concepts such as the direction of displacement, vector quantities, or negative magnitudes do not affect absolute values as they remain positive or zero.