A way of measuring. The number 100 (which stands for the whole amount) is usually divided into 100 smaller, but equal, parts, each called a percent. So a percentage usually refers to a certain number of parts within the whole. Therefore, 6% is 6 units out of 100% (the whole). If you have invested $100, and you earn 8% interest on the money, you will earn 8 parts of the whole, or $8. A percentage explains a number in relation to the whole.