What does "twerking" even mean??

I think it's safe to say that Miley Cyrus has become very good at keeping us all on our toes. Between all of the rumors about her and her fiancé, Liam Hemsworth, possibly splitting up (& then possibly getting back together) and all of the buzz that came with her dramatic hair change, Miley Cyrus is good at keeping us all interested.

Recently, Miley Instagramed a photo of her dressed in a unicorn onesie. Needless to say, this came across as slightly strange. At least until she later released a video of her twerking to J Dash and Flo Rida's "WOP." Truthfully, I had absolutely no idea what "twerking" even was until i saw this video. So thank you Miley for broadening my horizon.