"20%" refers to a fraction that represents one-fifth of a whole. In percentage terms, it means that for every 100 units, 20 units are being considered. This concept is commonly used in various fields, including finance, statistics, and everyday calculations, to express proportions or discounts. For example, if a product costs $100 and is on sale for 20% off, the discount would amount to $20, making the final price $80. Understanding percentages like 20% is essential for making informed decisions in budgeting, shopping, and analyzing data.