What do fake brands, counterfeit goods, parallel imports, and copycat versions mean? What's the difference? Which one is legal, a knockoff or a counterfeit? I bought a watch from Hangbei...

Fake brands and counterfeit goods refer to things produced by a manufacturer using someone else's brand without authorization. Shanzhai not only includes fake brands and knockoffs, but also refers to counterfeit and shoddy products, all of which are illegal. It's possible that what you're talking about isn't genuine, but I can't be sure since I haven't seen it.