Type classes:

• Eq: Any objects that can be compared for equality
• Ord: Any objects that can be ordered
• Show: Any objects that can be shown as a string (most types bar functions) (show :: (Show a) => a -> String)
• Read: Any objects that can be shown as a string ( read :: (Read a) => String -> a)
• Enum: Any objects whose value can be enumerated (anything a/b you can use in [a..b]
• Bounded: Int, Char, Bool
• Num: Int, Integer, Float, Double
• Floating: Float, Double
• Integral: Int, Integer

Types can be instances of multiple type classes as some type classes cover subset of other type classes.