Why is it classified as a fossil fuel?
Fossil fuels are found within the rocks of the Earth's surface. They are called fossil fuels because they are thought to have been formed many millions of years ago by geological processes acting on dead animals and plants, just like fossils.
Coal, oil and natural gas are fossil fuels. Because they took millions of years to form, once they are used up they cannot be replaced.
As time passed, layer upon layer of peat built up. The pressure from these layers and heat from below the Earth's crust gradually changed the material into coal.
Peat is not a fossil fuel, not by definition, although some people are now trying to call it an "un-renewable" fuel source, although it does renew. Political agencies are now classifying peat as a fossil fuel because in some areas it it possible to use up a local supply faster than it can renew. It is a classification for economic purpopses. That doesn't change the fact that it is not the same.