Question

what are fossils ? how are they formed

Answer 1

fossils are evidence of any extinct or remains of existing species.
They are formed when the organism die and get buried into the earth and after a long period they when a thick layers of soil are formed above it fossils are formed.
hope the answer is right.

Answer 2

The evidence of exist life forms preserved by the means of different natural processes are called the fossil's.
Usually,when organism die,their bodies will decompose and be lost.But every once a while,the body or at least some parts maybe in an environment that does not let it decompose completely.And this is how they are formed.