Prelude> :i ShowS
type ShowS = String -> String -- Defined in `GHC.Show'

It is a type of a function? I cannot understand this type, and don't know how to create functions of this type.

And this function "shows"

Prelude> :i shows
shows :: Show a => a -> ShowS -- Defined in `GHC.Show'

I don't know how this function works.