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, a constant function is represented by a horizontal line on a coordinate plane. The line's height corresponds to the constant value, while the horizontal axis represents the input values. This characteristic makes constant functions easy to identify and understand, as they do not change with varying inputs, unlike other types of functions such as linear functions or quadratic functions.