Overview
Sushi (寿司 or 鮨) is Japan's most iconic dish abroad and a firm favorite among locals. In Japan, sushi is typically reserved for special occasions like celebrations.
Historically, "sushi" referred to fish pickled in vinegar for preservation. Today, it means vinegared rice paired with various toppings. There are many sushi varieties. Popular ones include:

Small hand-pressed rice mounds topped with fish, shellfish, or other ingredients. Common nigiri toppings include tuna, shrimp, eel, squid, octopus, and tamago (fried egg).

Rice cups wrapped in nori seaweed and filled with seafood. Popular gunkan fillings are sea urchin and various fish roe.

Rice and fillings rolled in nori sheets. Rolls vary in ingredients and thickness. Inside-out rolls are popular abroad but rare in Japan.

Hand-rolled cones of nori filled with sushi rice, seafood, and vegetables.

Pressed sushi where fish is layered over rice in a wooden mold. The photo shows trout oshizushi sold as a popular ekiben (train station lunch box).

Simple, affordable sushi where rice is stuffed into deep-fried tofu pouches (aburaage).

A bowl of sushi rice topped with scattered seafood, mushrooms, and vegetables. It resembles seafood donburi but uses seasoned sushi rice.