I have no idea what the difference between cod and haddock is though

They're quite similar -- flakey white fish, served as largeish fillets. Haddock has a slightly denser texture to the flesh, and comes apart in firmer flakes. Personally I prefer it to cod, but as Pen say, that maybe just be a north/south thing. They're both perfectly nice and equally traditional, anyway.


So cheese fryit = fried cheese, or did misunderstand something?

I'm just guessing, but if it's something like a fishcake, then it will be a mixture of cheese and potato shaped into a thickish burger-shape and deep fried. Possibly, having Googled, with onion in it too.