What does the term "domain" refer to in relation to functions?

The term "domain" in relation to functions specifically refers to the set of input values that a function can accept. When we discuss functions, we often describe them in terms of their variables, and the domain outlines all the permissible values for the input variable, usually denoted as (x).

For example, in the function (f(x) = \sqrt{x}), the domain would be all non-negative real numbers, since you cannot take the square root of a negative number in the set of real numbers. The concept of domain is critical because it establishes the valid inputs for which the function operates properly.

In contrast, the other options refer to different features of functions. Maximum values are related to the outputs and describe the highest points the function can reach. Output values of a function refer to the set of possible results obtained after inputting values from the domain; this is known as the range. The graphical representation of a function illustrates how input and output values are related visually but does not refer to the domain itself.