Non-linear regression is a statistical method used to model relationships between variables when the relationship is not a straight line. Unlike linear regression, which assumes a constant rate of change, non-linear regression can accommodate curves and more complex patterns. This makes it useful for analyzing data in fields like biology, economics, and engineering. In non-linear regression, the model is defined by a mathematical equation that includes non-linear terms. The goal is to find the best-fitting curve that minimizes the difference between observed data points and the predicted values. This approach allows for more accurate predictions in situations where linear models fall short.