An opinion states a person's or group's thoughts, feelings, or beliefs about something. It cannot be proven true, because it relies on the feelings, thoughts, or beliefs of a specific person or group. For example, an opinion would be: 'Pizza is the best food on Earth!' You know this is an opinion because it tells you about a feeling or belief. Someone may think pizza is the best food, but another person might think it is not. It cannot be proven true.