Sashimi is a Japanese delicacy primarily consisting of very fresh raw seafood, sliced into thin pieces about 2.5 cm (.98 in.) wide by 4.0 cm (1.6 in.) long by 0.5 cm (0.2 in.) thick, but dimensions vary depending on the type of item and chef. Served with only a dipping sauce (soy sauce with wasabi paste or other condiments such as grated fresh ginger, or ponzu), depending on the fish, and simple garnishes such as shiso and shredded daikon radish, says Wikipedia.
In Japanese cuisine, sushi (寿司, 鮨, 鮓 ?) is vinegar rice, usually topped with other ingredients, including fish dishes.