Okay kiddo, so rakfisk is a kind of food that comes from Norway. It's made from a type of fish called trout, which has been soaked in salt water and left to ferment for a few months.
During that time, lots of little bacteria grow on the fish, which makes it taste really different from plain old trout. Some people love the taste, but others think it's a bit too strong or stinky.
People often eat rakfisk on bread or crackers, and sometimes they put things like onion, sour cream, or mustard on top. It's eaten around Christmas time in Norway, and some families even make their own rakfisk at home.
So overall, rakfisk is a special kind of fish that's been fermented for a long time, and some people really love the taste!