A constant function is a type of mathematical function that always produces the same output, regardless of the input value. In simpler terms, no matter what number you put into the function, the result will always be the same. For example, if a function is defined as f(x) = 5 , it means that for any value of x , the output will always be 5. Graphically, constant functions are represented as horizontal lines on a coordinate plane. The line's height corresponds to the constant value, while the horizontal axis represents the input values. This means that the function does not change as you move along the x-axis, illustrating the idea that the output remains unchanged.