In japan they eat sushi.what is it?

Sushi (すし, 寿司, 鮨?) is a Japanese food consisting of cooked vinegared rice (鮨飯 sushi-meshi?) combined with other ingredients (ネタ neta?), seafood, vegetables and sometimes tropical fruits. Ingredients and forms of sushi presentation vary widely, but the ingredient which all sushi have in common is rice (also referred to as shari (しゃり?) or sumeshi (酢飯?)).
Sushi can be prepared with either brown or white rice. Sushi is often prepared with raw seafood, but some common varieties of sushi use cooked ingredients or are vegetarian. Raw fish (or occasionally other meat) sliced and served without rice is called "sashimi".