GCD

The Greatest Common Divisor (GCD) of two numbers is the largest whole number that divides both of them without leaving a remainder. For example, the GCD of 8 and 12 is 4 because 4 is the biggest number that evenly divides both 8 and 12. It helps identify the common factors between numbers and is useful in simplifying fractions or solving problems involving ratios. Finding the GCD can be done through methods like listing common factors or using the Euclidean algorithm, which efficiently computes it by repeatedly applying division and remainders.