An opinion is a belief, judgment, or statement that is not conclusive, rather than facts, which are true statements. It is a conclusion that certain facts, ideas, or beliefs are true or false, and it can be reasoned that one opinion is better supported by the facts than another, by analyzing the supporting arguments. Different people may draw opposing conclusions (opinions) even if they agree on the same set of facts. Opinions rarely change without new arguments being presented. In casual use, the term opinion may be the result of a persons perspective, understanding, particular feelings, beliefs, and desires. Collective and professional opinions are defined as meeting a higher standard to substantiate the opinion.

Opinions can be expressed in different ways, such as:

• Public opinion: The aggregate of individual attitudes or beliefs held by a population (e.g., a city, state, or country), while consumer opinion is the similar aggregate collected as part of marketing research (e.g., opinions of users of a particular product or service).

• Group opinion: The aggregation of opinions collected from a group of subjects, such as members of a jury, legislature, committee, or other collective decision-making body. In these situations, researchers are often interested in questions related to social choice, conformity, and group polarization.

• Formal expression of judgment or advice by an expert: For example, a doctors opinion on a medical condition.

It is important to distinguish between fact and opinion. A fact is a statement that can be verified and proven true or false through objective evidence, while an opinion is a statement that expresses a feeling, an attitude, a value judgment, or a belief, and it is neither true nor false.