What is this vegetable and how should it be prepared?

Every time I visit my local Chinese supermarket I’m fascinated by the exotic veggies. One in particular is a long, smooth white root vegetable, like a giant white carrot. I’d love to try it but I have no idea how to prepare it, and as I don’t know the proper name of it, I’ve not had much success searching online. Does anyone know what it is and what to do with it? Oh and if you know what it tastes like too, that would be even better.