C², or "C-squared," is a term often used in various fields, including mathematics and physics. In mathematics, it typically refers to the square of a variable or constant, represented as C × C. This concept is fundamental in algebra and is used in equations and formulas to describe relationships between numbers. In the context of physics, C² is commonly associated with the speed of light, denoted as c. According to Einstein's theory of relativity, the equation E = mc² illustrates the relationship between energy (E), mass (m), and the speed of light. This equation shows how a small amount of mass can be converted into a large amount of energy.