How does non-blocking I/O work in Node.js?

16 Tem 12:45

I thought I really understood how the event loop manages asynchronous I/O, but I get confused in some edge cases. For example, I know what non-blocking I/O is, but when does the 'blocking' part specifically come into play in the fs module? What exactly are we waiting for during a file system read? Also, while this structure improves efficiency, in what scenarios can it limit our performance? For those who are proficient in the topic, could you also explain the role of buffers like I'm trying to?