From another thread:
http://theconversation.com/no-youre-...r-opinion-99781. sharing - you express your opinion. You may not care about others opinions because you know that no matter what they may say, it won't change your mind..
2. discussion - Someone expresses his opinion, you ask question in order to understand his opinion better. You do care about others opinion because you may change your mind.
3. debating - You try to change others mind.
4. personal attack - It's about the person and not about the subject.
Worth a read!