The hand-formed sushi topped with a piece of fish is called nigiri. More precisely, nigiri-zushi consists of a small mound of vinegared rice shaped by hand and topped with seafood, usually sliced fish. Chefs may add a thin strip of nori or a dab of wasabi between the rice and topping.
Nigiri is associated with modern sushi in Edo—present-day Tokyo. Hanaya Yohei is widely credited with popularizing it around 1824 as a convenient fast food for the city’s working population. Unlike older fermented sushi, nigiri was designed to be eaten immediately.
A common mix-up is sashimi, which is raw fish or seafood served without sushi rice. Temaki is hand-rolled cone-shaped sushi, while maki refers to rolled sushi made with a bamboo mat or similar technique. Although salmon, tuna, shrimp, eel, and sea bream are common toppings, nigiri does not require the fish to be raw; cooked or lightly seared seafood can also be used.