You can find a basic overview at: http://asiafood.org/glossary_2.cfm
The first time I encountered this plant was at a local Korean restaurant where a buddy of mine from work and I used to go to lunch. I wanted to know what it was, and so I asked the very brash, but somehow still likeable Korean waitress. (Who barely spoke English.)
Pointing to it, I asked "What is this?" She shrugged, and said "Root." I pressed "Yes, but what kind
of root?" She glared at me for a moment, then repeated "ROOT!" at a much louder volume, and with that whirled and stalked off.
I only discovered what it was when I happened across a frozen bag containing slices of it with its distinctive holes in the local Costco.