Non-Linear Programming (NLP) is a branch of mathematical optimization that deals with problems where the objective function or the constraints are non-linear. Unlike linear programming, where relationships are represented by straight lines, NLP involves curves, making it more complex. This type of programming is used in various fields, including economics, engineering, and operations research, to find the best possible solution under given conditions. In NLP, the goal is to maximize or minimize a specific function while satisfying certain constraints. Techniques such as gradient descent and Lagrange multipliers are often employed to find optimal solutions. Non-linear programming is essential for solving real-world problems where relationships between variables are not simply proportional.