Kimchi is fermented vegetables. It is usually cabbage, but can be any number of other vegetables grown in Korea. It has a pungent, hot flavor and varies from cook to cook. As Clemenza was saying, Fort Lee is "Little Korea" and if you want to try it go to a restaurant in that town.
There's also a "little korea" over by Herald Sq. I go there sometimes to buy electronics cheap. Though usually when in the area, I'll hike up to 49th and B'way to eat Japanese at Sappora.
I find that the first two bites of kim chi vegetables, after a long abstinence, are delightful- the third is banal and I can't handle any further atempts at all.