The absolute value of a number is simply the distance that number lies away from 0 on the number line. Absolute value eliminates the "direction" traveled to get there. It's like saying that you walked 3 meters frontward versus 3 meters backward. You walked 3 meters in different directions from where you started!
Some examples: #|-3| = 3# and #|3|=3#
#|-9| = 9#
#|5| = 5#
#|3-11| = |-8| = 8#
With a number line in front of you, you can point to any location and tell someone how far it is from 0 by just ignoring whether that point is to the left or right of 0. Think of that as "absolute value"!