Not resembling what most people visualize as a radish, the long daikon, looks more like a parsnip.  The daikon is the Japanese name this large white radish, mooli the Indian and West Indian name.  In Japan you will often find daikon grated and eaten as a condiment with dishes like sushi and sashimi like the green horseradish , wasabi.  In India it is eaten cooked or raw.

You should choose large firm daikons with fresh green tops, and prepare by peeling prior to slicing, grating or eating.