What are Eff and Aff?
<p>What is the relationship between the Purescript types <a href="https://pursuit.purescript.org/packages/purescript-eff/0.1.2/docs/Control.Monad.Eff#t:Eff"><code>Eff</code></a> and <a href="https://pursuit.purescript.org/packages/purescript-aff/0.16.1/docs/Control.Monad.Aff#t:Aff"><code>Aff</code></a>? Is it possible to convert between them?</p>

<p>I'm just starting out with Purescript coming from Haskell, and it seems like both types roughly serve the role that <code>IO</code> has in Haskell. Is that fair to say?</p>