I think the author meant "just" as in: it is only another name. In Haskell, you can make an infix operator out of a function by putting it between backticks. Thus, `fmap` and <$> are synonyms. For example:

    (subtract 3) <$>    [1,2,3,4]  -- =[-2,-1,0,1]
    (subtract 3) `fmap` [1,2,3,4]  -- =[-2,-1,0,1]