A more thorough explanation:

Definition: Mileage refers to the distance traveled in miles between two points. It can also refer to the distance a vehicle has traveled as shown on its odometer. Additionally, it can refer to an allowance paid to cover travel expenses, such as for a witness or public employee.

For example, if you drive from New York City to Boston, the mileage between the two cities is approximately 215 miles. If your car's odometer reads 50,000 miles, that means your car has traveled that distance since it was manufactured. If you are a witness in a court case and are required to travel to the courthouse, you may be given a mileage allowance to cover your travel expenses.

These examples illustrate the different ways in which the term "mileage" can be used to refer to distance traveled and travel expenses.