Opinions and advice are not necessarily the same thing.It depends what you are talking about.
What Rooster and Blew said. 乂º◡^乂
There is a distinction, giving my opinion is just sharing what I think about a matter, giving advice would imply I'm very competent in the topic which is not always the case.
As is all 'knowledge' and every human utterance. Just opinions.
And every opinion matters.
Giving advice is giving your opinion of what the person should do.
Unless you were ever in the exact situation that person was asking advice for - in which case your advice MAY be what you did. Otherwise, it is still just your opinion.