There is a big difference between facts and opinions. In short, facts are solid and unchanging and opinions are subjective and changeable.
Facts are things with which no one can argue. Dictionaries and encyclopedias are full of facts. If you ever wonder what a "bug" is, you can look it up in the dictionary and it will give you the facts about "bugs." However, there are several different kinds of bugs. People can have their own opinions about which kind of "bug" is really a bug.
Opinions are things that we form based on the information we receive. They are things that we can (and frequently do) argue about. I think that a bug is something small that can be squished under ones foot. The key phrase is "I think." You may think that a bug is an annoying sickness that you can catch from someone else. We both have our opinions, but the facts say that we are both right.
I think that is possible to confuse facts and opinions, which is why it is so important to be careful how we analyze our information. Frequently, people like to state their opinions as facts because it makes it sound more authoritative and convincing. However, it is misleading. The facts are "just the facts" and what we add to them are our own opinions.
Sometimes, our beliefs determine what we believe are the facts. Here it is often difficult to separate facts and opinions. So, my opinion has now changed. I believe that the fact is as follows: Some facts and opinions are easily identified, but others are harder to separate and discern.