The natural logarithm, denoted as ln, is a mathematical function that represents the logarithm to the base e, where e is an irrational number approximately equal to 2.71828. It is commonly used in various fields such as mathematics, physics, and engineering to solve problems involving exponential growth or decay. The natural logarithm has several important properties. For instance, ln(1) equals 0, since e^0 equals 1. Additionally, the natural logarithm is the inverse function of the exponential function, meaning that if y = ln(x), then e^y = x. This relationship makes it a valuable tool for simplifying complex equations.