This tag should be used for questions about freelancing problems that involve freelancing websites like oDesk, eLance, etc. For software support questions, see that vendor's customer support page. Do NOT use this tag for questions relating to developing websites for customers.
A freelance website is a site which links freelancers to clients and (more specifically) client projects, often through a bidding process. Examples include oDesk, eLance, etc.
This tag is not intended to be for questions regarding the development of websites for customers.
While this question, How to get work on freelancer.com as an existing contractor but new to freelancer.com?, primarly targets non-experts, it's a good example of when to use this tag. The question is more of a marketing question.