A fact can be proven, and an opinion is a belief.
Conclusions made on the basis of unstated or stated evidence are called "inference".
Inference is mainly using observation as well as background in order to reach a logical conclusion.
We practice inference during our everyday lives.
Example:
When you enter your office and find everything clean and in place. You conclude that the housekeeping has cleaned the room
with the smell of steaks in passageways (olfactory=sense of smell)
