Haskell: Where vs. Let

Question

I am new to Haskell and I am very confused by Where vs. Let. They both seem to provide a similar purpose. I have read a few comparisons bet

Answer 1

Legal:

main = print (1 + (let i = 10 in 2 * i + 1))

Not legal:

main = print (1 + (2 * i + 1 where i = 10))

Legal:

hasVowel [] = False
hasVowel (x:xs)
  | x `elem` vowels = True
  | otherwise = False
  where vowels = "AEIOUaeiou"

Not legal: (unlike ML)

let vowels = "AEIOUaeiou"
in hasVowel = ...