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Haskell is pure functional — functions don't have side effects (mostly). Anything that touches the outside world goes through IO.

main :: IO ()
main = do
    putStrLn "Hello, World!"
    putStrLn "Ship That Code"

The entry point is main of type IO () — an IO action that returns unit. The do block sequences IO actions.

putStrLn prints a string with a newline. putStr skips the newline. The :: is a type annotation — name :: Type.

Type signatures are usually optional (Haskell infers them) but it's idiomatic to annotate top-level bindings for documentation and to catch type errors at the right place.