A cent is a very small unit of money. In the US, one cent is the same thing as one penny.
A cent is 1/100 of a dollar — in other words, there are 100 cents in a dollar. Many other currencies have a cent as well, including the European Union, Estonia, and Hong Kong, representing 1/100 of the basic unit of money. The word cent comes from the Latin centum, "hundred." In Middle English, cent meant "one hundred," but by the 1600s it came to mean "one hundredth."