Modular Exponentiation is a method used to efficiently compute large powers of numbers while keeping the results manageable by taking the modulus. Instead of calculating the full power and then applying the modulus, this technique breaks the problem into smaller parts, using properties of exponents and modular arithmetic. This is particularly useful in fields like cryptography, where large numbers are common. The process involves repeated squaring and reducing the intermediate results modulo a given number. This approach significantly reduces the number of calculations needed, making it feasible to work with very large exponents without running into overflow issues or excessive computation times.