>>= -package:basement -package:loc package:base

Sequentially compose two actions, passing any value produced by the first as an argument to the second. 'as >>= bs' can be understood as the do expression

do a <- as
bs a

An alternative name for this function is 'bind', but some people may refer to it as 'flatMap', which results from it being equivialent to

\x f -> join (fmap f x) :: Monad m => m a -> (a -> m b) -> m b

which can be seen as mapping a value with Monad m => m a -> m (m b) and then 'flattening' m (m b) to m b using join.