The function f(x) = x is a simple linear function where the output value is always equal to the input value. This means that for any number you put into the function, it will return that same number. For example, if you input 3, the output will also be 3. This function represents a straight line on a graph that passes through the origin (0,0) with a slope of 1. In mathematical terms, this function is often used as a basic example in algebra and calculus. It serves as a foundation for understanding more complex functions and relationships. The graph of f(x) = x is a diagonal line that helps illustrate concepts like slope and intercepts in coordinate geometry.