The function `calculateSum(5, 10)` is designed to add two numbers together. In this case, it takes the numbers 5 and 10 as inputs. The function processes these values and computes their total. When executed, `calculateSum(5, 10)` will return the result of 5 + 10, which equals 15. This simple operation demonstrates how functions can perform arithmetic calculations by taking parameters and returning a result based on those inputs.