It means how far is -5 from zero on the number line.
What do you think that the answer is?
This is known as the "absolute value"...it represents the distance on the number line from 0 to the number in the absolute value bars.....in this case, the distance from 0 to -5 is just 5. And since distance is always ≥ 0, then absolute value is always ≥ 0....
This means how many spaces from zero it is and the answer would be 5 since it is 5 units from 0.