What is a discount in a convertible note?

A discount in a note sets a percentage reduction at which the convertible note will convert relative to the next qualified priced round. Effectively this permits an investor to convert the principal amount of their loan (plus any accrued interest) into shares of stock at a discount to the purchase price paid by investors in that round. Discounts range from 0% to as high as 35% with 20% being common.