There Haskell people go again =) You try to define something in simple normal terms, and off they go adding highly specific and technically correct words to what was supposed to be a simple explanation.

(I'm not a Haskell expert, I dabble, done CIS194, half of RWH, and I have no idea what you said -- which is a common problem I run into in the Haskell world, lots of super helpful people that have forgotten what its like to not speak their language)