Nigiri, or nigirizushi (握り寿司) is a style of sushi in which a piece of fish, shellfish, egg, or vegetable (called neta) is placed on a bite-sized oblong of vinegared rice (called shari).
The term nigirizushi means "hand-pressed sushi", and the hand-assembly of the sushi, with the shari formed in the chef's hand before the neta is applied to it, optionally with a small amount of wasabi or a brushing of sauce, is key to the dish.