Sashimi is thinly sliced, raw seafood. Many different kinds of fish (and other types of seafood) are served raw in the Japanese cuisine. Of course, the fish has to be as fresh as possible. Sashimi can be eaten just as sashimi or as nigiri zushi, in which case the sashimi piece is put on top of a small ball of sushi rice.
Sashimi pieces are dipped into soya sauce before they are eaten. Depending on the kind of sashimi, wasabi or ground ginger is usually mixed into the soya sauce.