Is there a difference between 有趣 and 有意思? They seem to mean the same thing, but I've seen 有意思 quite a few times in my books, and never 有趣. When is 有趣 used and why (especially in comparison with 有意思)?
有趣 - fun
有意思 - interesting


To break the vocabulary literally, we have 有/趣 and 有/意思. The word 有 carries the meaning similar to "there is something" or "it has something". 趣 can be interpreted as "fun". 意思 can be translated to "meaning".

So, these two vocabularies can be broken down literally as:

X有趣 - there is fun in X / X is fun
X有意思 - X is interesting