What are you talking about? Sushi is sushi. Nevertheless, I shall try to help you.

Be on the lookout for vinegared rice with fish or some other ingredient on top. That's a variety called nigiri. Also, vinegar rice in a roll is another type of sushi called maki. An example of maki is tekkamaki or, to use a more common example (at least, where I live), California rolls. Keep in mind that most maki do not resemble California rolls...rather, they have the seaweed on the outside. Inari-zushi is another kind of sushi, but there's usually no fish. It's just a pouch of fried tofu with vinegar rice on the inside. The last type of sushi is called temaki. It's a large piece of seaweed rolled up into a cone shape, with the ingredients spilling out of the wide side. Chirashi is also arguably sushi, since it has sushi rice mixed with raw fish.

Hope that helps.