The first sentence states a fact.
Juan Ponce de León was the Spanish explorer who named Florida.
It can be proved by reading about the history of Florida.
The second sentence states an opinion.
Juan Ponce de León was an important person in American history.
Important shows what a person believes, thinks, or feels. Another person might have a different opinion about whether he was important in American history.
Which sentence states a fact?
A: Juan Ponce de León was an important person in American history.
B: Juan Ponce de León was the Spanish explorer who named Florida.