What is Panko?
Panko are basically japanese breadcrumbs. It is used in all kind of dishes, and can be found mainly in those that include fish and seafood.
Panko is commonly related with deep-fried dishes. One of its most common uses in sushi, is soaking an inside-out roll in tempura, then rolling it in panko, and lastly deep frying,
Some use panko to decorate and enrich inside out rolls with out frying the entire roll by frying the panko alone, and then spreading it over the inside out sushi roll just before cutting. A bit of tightening with the rolling mat and voila. The sushi roll is immediately enriched both in color and flavor.
Although the two are likely to bee seen together, panko and tempura are not the same thing at all. Both are used for coating, but unlike the tempura the panko is not sticky, and therefore sometimes used together with the first, in order to stick well enough during the frying process.