How far a number is from zero.
Examples:
6 is 6 away from zero, so the absolute value of 6 is 6
−6 is 6 away from zero, so the absolute value of −6 is 6
In other words it is the magnitude or size of a number, no negatives allowed.
The symbol "|" is placed either side to mean "Absolute Value", so we write: |−6| = 6
Try it yourself: