A mathematical constant is a special number that has a fixed value and is universally recognized in mathematics. These constants often appear in various mathematical equations and formulas, providing essential relationships between different mathematical concepts. Examples include π (pi), which represents the ratio of a circle's circumference to its diameter, and e, the base of natural logarithms. Mathematical constants are crucial in fields such as geometry, calculus, and number theory. They help simplify complex calculations and provide a foundation for understanding mathematical principles. Their significance extends beyond pure mathematics, influencing areas like physics and engineering.