Hi Totte.....The word Sushi means "sour rice"
Sushi rice is made by rinsing and soaking the rice, then cooking on low to allow it to absorb the water slowly.
A mixture of rice wine vinegar, Sake, and/or Mirin (Sweet rice wine), and sugar are heated to dissolve the sugar, then added to the already cooked rice and fluffed.
Sushi rice with fish is called "Nigiri Sushi)
Fish alone is called Sashimi
The fish is not "cooked" or made safe by the vinegar.