What is the difference between a meter and a gauge?
What is the difference between a meter and a gauge? An example of a meter is a parking meter where it shows you how much time you have left. Gauges also measure how much of something we have. Gauges are most often used in situations where the thing we are measuring changes all the time, such as in the measuring of volume of something we are using.
Why do most countries use different railway gauges?
If locomotives were imported from elsewhere, especially in the early days, the track would be built to fit them. In some cases standard gauge was adopted, but many countries or companies chose a different gauge as their national gauge, either by governmental policy, or as a matter of individual choice.