Yes, it is possible for the domain and range of a function to be the same. This occurs when the function maps each input value to itself. For example, the function f(x) = x is a simple example of such a function, where both the domain and the range are the set of all real numbers. In this case, the function takes each real number as input and maps it to itself, so the output is the same as the input.
However, this is not always the case for all functions. Some functions may have different domains and ranges, depending on the restrictions imposed on the inputs and outputs. In general, the domain is the set of all possible inputs for a function, while the range is the set of all possible outputs.
