A real function is a mathematical relationship where each input from a set of real numbers corresponds to exactly one output, also a real number. This means that for every value you plug into the function, you get a specific result. Real functions can be represented using equations, graphs, or tables, making them versatile tools in mathematics. Common examples of real functions include linear functions, quadratic functions, and trigonometric functions. These functions can be used to model various real-world situations, such as physics, economics, and engineering. Understanding real functions is essential for studying more complex mathematical concepts.