The Distance Function is a mathematical concept used to measure the distance between two points in a given space. It quantifies how far apart these points are, often represented as a numerical value. In a two-dimensional space, the most common distance function is the Euclidean distance, calculated using the Pythagorean theorem. Distance functions can also be applied in various fields, such as computer science, physics, and statistics. For example, in machine learning, distance functions help in clustering data points by determining how similar or different they are from one another.