The equation "x = y" represents a mathematical statement indicating that the value of x is equal to the value of y. This means that whatever quantity x holds, y holds the same quantity. This concept is fundamental in algebra and is used to express relationships between variables. In practical terms, if you know the value of one variable, you can determine the value of the other. For example, if x is 5, then y must also be 5. This equality is crucial in solving equations and understanding functions in mathematics.