The Roman numeral system is a numeral system originating in ancient Rome that uses combinations of letters from the Latin alphabet. The main symbols are I (1), V (5), X (10), L (50), C (100), D (500), and M (1000). Numbers are formed by combining these symbols, adding their values, and following specific rules, such as not placing more than three of the same symbol in a row. This system was widely used throughout the Roman Empire for various purposes, including trade, military, and timekeeping. Although it has largely been replaced by the Arabic numeral system, it is still used today in certain contexts, such as clock faces and book chapters.