An opinion is something someone forms based on their feelings and experiences. It does not rely on facts. A fact is something that can be validated by others and direct observation.
A fact is something that can be tested and proven to be true. An opinion is something that a person thinks or believes , but which cannot be fully proven. Others may hold a different opinion.
A fact is something that is proven to be true. An opinion is a person's thoughts on something and can vary person to person. An opinion can not be proven.