Throughout the entire book I constantly use the words "goal" or "task." On one hand it may seem that there is no difference at all between them. But I tried to maintain a boundary between these terms. Although, because the book turned out to be quite large and these words appeared in every chapter, I may sometimes have used one of them incorrectly, or conversely deliberately used a word that was not quite fitting in order to avoid tautology or convey a clearer meaning.
If we answer the question directly about what the difference is, in my understanding it is as follows: a goal is something big and long-lasting in time, something very important in your life. For the word "goal" you could pick the synonym "desire," although I do not like that word very much and tried not to use it in the book.
Almost no goal can be completed in one go, simply by taking it and doing it. Most likely it will require you to break it into small parts and sequentially complete those parts over a long period of time. These very broken-down parts I call tasks. I also want to draw attention to the fact that in many productivity books instead of the word "task" they may use the word "event." You can especially often encounter mentions of events as a term among those who manage their daily affairs not as a list but as a calendar. Then such entries in their calendar can quite logically be called events.
