They are two different pairs of shoes. One is about application and the other is an inherent property of the definition.
Partial application or a partially applied function, is a function that is in the middle of being applied to its parameters and hence in some form incomplete. A partial function on the other hand is a a function that is not total i.e partial. What's a total function? We go into the details below.
`f :: Int→Int→Int`, f is a function that takes two `Int`s and returns an `Int`, that’s the short story.
Reading type signatures is the first step to understanding what a function does or how a complex program is composed together. It took me some time to get my head around them and I have seen people struggle with them, especially developers coming from dynamic languages. Even for developers from strongly typed languages like Java they are alien. The text makes them more accessible. My recommendation would be to plough through it without accessing the references in footnotes and then re-read it more slowly with references. If something is still unclear or could be improved - do reach out (@ppurang).
Derived from [Coco](http://satyr.github.io/coco/) and very like [CoffeeScript](http://coffeescript.org/). Even comes with it's own prelude.