Difference between various Unity help areas , Default, Help Room, META and Moderators?

Unfortunately the use of the different areas isn't explained in a central spot. I'll explain them briefly:

Default

The default space is ment for the "usual" questions. That are questions that arise from the usage of Unity and it's API. The questions here should mainly revolve around conceptional questions

Help Room

The Help Room has been added recently since Unity Answers was flooded with "poor" questions. "Poor" doesn't necessarily mean that they are bad (though, a lot are). It's ment for questions that are only partially related to Unity. That includes questions about general programming issues (trouble understanding basic OOP concepts or C# syntax). This also includes all "I received compiler error XYZ / exception XYZ" questions as well as pure debugging questions. So when the problem isn't about Unity but about a specific issue that a user has with his code that is related to a poor understanding of basic concepts.

Unity Answers is not a general programming Q&A site. We do not teach programming here. It's a knowledge base that should help all Unity users when they have specific questions about the development with Unity.

META

The META space exists in most Q&A sites. It's ment for questions about UnityAnswers itself. Your question here is a prime example for the META space ^^.

Moderator

The Moderator space is basically a "sub section" of the META space. It's ment for questions about the rules / conventions you should use when you reached a high enough "karma" / reputation level so you can view the moderation queue. If you participate as moderator and something is unclear you can ask for clearance here.

Moderation queue

The moderation queue is a seperate area that only moderators can view. It contains posts of new users which have less than 15 karma points. All posts from users with less than 15 karma points are automatically hold back in the moderation queue and a moderator has to "approve" it. We introduced this since UnityAnswers was heavily misused for spam / advertising. A moderator might send a post back to the moderation queue when there's a problem with the post (off-topic, advertisement, bad language)

I suggest you read through the UserGuide and the FAQs

If you also act as Moderator, there are seperate moderator guidelines. Even if you're not a moderator it might be interesting so you understand when a question / answer / comment might be rejected.