In mathematics, the domain of a function is the set of all possible input values for which the function is defined, while the range is the set of all possible output values that the function can produce. The domain is represented along the x-axis, while the range is represented along the y-axis.

For example, consider the function f(x) = 1/x. The domain of this function is all real numbers except 0, since division by zero is undefined. Therefore, the domain is (-∞,0) U (0,∞). The range of this function is also all real numbers except 0, since the function approaches 0 but never touches it. Therefore, the range is (-∞,0) U (0,∞) .

It is important to note that the domain and range of a function can be determined by looking at the functions graph, but this is not always the case. Sometimes, it is necessary to use algebraic methods to determine the domain and range.