WordPress Answers, more commonly known as WordPress Stack Exchange (WPSE), is part of Stack Exchange question and answer site network. It was created on initiative of network users and is not affiliated with the WordPress project.
The basic activities on site are asking, answering and voting. You are not required to register an account on the site in order to ask or answer questions. However, registration is recommended so that your reputation and attribution of your questions and answers are tracked correctly.
Popular WordPress extensions (especially plugins) can gather considerable amount of questions on site and it is customary to tag them with plugin-name and theme-name. If you are developer or expert on such extension you can keep an eye on tag page and subscribe to it via RSS.