What's a promise? This article seems to assume you know that when you start reading. Here's my understanding: Sometimes in code you get into callback hell. A

What's a promise? This article seems to assume you know that when you start reading. Here's my understanding: Sometimes in code you get into callback hell. A callback calls a callback calls a callback. Your code starts to grow horizontally more than vertically like this: callback1 callback2 callback3 callback3ReactionToFailure callback2ReactionToFailure callback1ReactionToFailure As a result, the code is hard to read because it doesn't flow sequentially. Promises are a solution to that problem. They let you take something that would be callback hell and write it sequentially. Keep in mind it's the blind leading the blind here. I just learned this term a month ago. Please correct me if I'm wrong. That said, I found http://promises-aplus.github.io/promises-spec/#terminology http://promises-aplus.github.io/promises-spec/#terminology to be more informative than the article itself (no offense)