I don't believe this is "the most practical explanation of closures out there" as the author claims, but it does present a use-case. The most important thing to grasp if you're fussed about naming concepts in JavaScript is the difference between a function, a scope [1], a closure [2], and an IIFE [3].

[1] https://developer.mozilla.org/en/docs/Web/JavaScript/Referen...

[2] http://unscriptable.com/2011/10/02/closures-for-dummies-or-w...

[3] http://benalman.com/news/2010/11/immediately-invoked-functio...