Natural logarithms, denoted as ln, are a type of logarithm that uses the mathematical constant e (approximately 2.718) as its base. They are commonly used in various fields, including mathematics, physics, and finance, to solve problems involving exponential growth or decay. The natural logarithm of a number is the power to which e must be raised to obtain that number. For example, if ln(x) = y, it means that e^y = x. Natural logarithms have unique properties, such as ln(1) = 0 and ln(e) = 1, which make them useful for simplifying complex calculations. They also play a crucial role in calculus, particularly in integration and differentiation.