Key Difference: A comment is considered as an observation or a statement that expresses a fact or an opinion on a matter. Opinions are subjective beliefs of either one person or a group of people and these need not be true.

A comment and an opinion are closely related as a comment is based on opinions. A comment basically refers to any statement made about a person, event or thing, while an opinion is a belief of a person. These are related as people usually make comments based mostly on opinions that they may have. Although comments can also be facts, they are more commonly opinion based statements.

A comment is considered as an observation or a statement that expresses a fact or an opinion on a matter. A comment can also be a written statement regarding specific matter. For example, after reading a book, the reader may be asked to provide a comment. The reader states, “The book was exciting in the beginning, but did not grasp my attention towards the end.” This would be considered as a comment based on the opinion of the reader. Another example would be a person walking down on the street sees a blue flower. He pauses and tells his friend to see the blue flower. This would be considered as a comment based on a fact.

Comments can also be considered as an explanation regarding an already written text or an object. For example, in computer programming, comments are added to the source code as an explanatory for that code. Comments are commonly used to refer to opinions or statements made regarding a certain subject.

Dictionary.com defines ‘comment’ as:

• A remark, observation, or criticism
• Gossip; talk
• A criticism or interpretation, often by implication or suggestion
• A note in explanation, expansion, or criticism of a passage in a book, article, or the like; annotation.
• Explanatory or critical matter added to a text.

Opinions are subjective beliefs of either one person or a group of people and these need not be true. Opinions are the result of emotion or interpretation of facts. An opinion can be supported by an argument, which can create two opposing opinions from the same set of facts. Opinions can be a result of a person's perspective, understanding, particular feelings, beliefs, and desires. These are various types of opinions: Public/consumer opinion, scientific opinion, legal opinion, judicial opinion and editorial opinion.

Public or consumer opinion is an important part of marketing and advertising, which takes the opinion of a group of people in order to see if a product will be successful in the market or no and if so, which type of audiences will it be most popular with. Opinions can vary and are not set in stone; they can also change from persuasion or circumstances. Opinions can also become facts, when proven and it is believed that almost all facts were opinions before they were proven. An opinion can be influenced by culture, religion, society, etc. Gossip and editorial columns are types of opinions.

Dictionary.com defines ‘opinion’ as:

• a belief or judgment that rests on grounds insufficient to produce complete certainty.
• a personal view, attitude, or appraisal.
• the formal expression of a professional judgment
• Law. the formal statement by a judge or court of the reasoning and the principles of law used in reaching a decision of a case.
• a judgment or estimate of a person or thing with respect to character, merit, etc.

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