Percentage subtracted from an initial amount.
A discount is a decrease in the initial value.
Example
If a TV with an initial sale price of $500 is sold for $400, then this is a reduction of $100, because 500 − 400 = 100.
This represents a 20% discount, because 100 ÷ 500 = 0.2 and 0.2 corresponds to 20%.