I just answered a question, and after my answer appeared, there was a button that said "Add Another Answer".
My understanding is that a good question should have a single "best" answer - that's why we can only award one "accepted answer" to any particular question.
Why then is there an option for one user to provide more than one answer to a question?
The short answer is that it's rare that adding multiple answers makes sense, but there are corner cases where it could be of use.
There's a good thread on MSO about this particular feature, here's a short summary:
You should post multiple answers if they are unrelated and
- they are too long to be in the same post or
- they are superficially similar, so having them in the same answer could be confusing or
- they are so dissimilar that having them in the same answer would be incongruent or
- one of them is likely to meet objection and the other approval or
- you really think it would be better to have them in different posts.
There's often more than one way to shave a camel. If the ways are different enough, you might want to post them separately so that they can stand on their own and be voted independently. That's a pretty big might, though, so that's why the site asks you if you really do want to post multiple answers.
There is really no point. It's more a matter of "why not" rather than "why." There are some corner but legit cases where answers truly are too long, but they're the exception not the rule.
In the context of StackOverflow, I've given multiple answers to the same question a couple of times. Usually it's two different sets of code with two different approaches. The community can pick the one they like and upvote it over the other.
In the arQAde, I imagine it would be much rarer for multiple different solutions from one person to require community selection, but still possible.
