There is quite a bit difference between the Ni and Ne function. There are also some similarities. They are both the perceiving function, and they are both intuitions, but they have different attitudes. And this makes them quite different from each other. As somebody who uses Ne as their second function, and was trying to figure out what Ni is like, I think I might have an idea or two about the differences.
The difference between Ni and Ne could be best described as the difference between the divergent and convergent thinking. And most if not all of the differences, that are between the divergent and convergent thinking can also be applied to Ne and Ni.
Ne is like a divergent thinking. Ne feels like looking for the next shining thing. I mean, it sounds ridiculus, but it is true. When Ne is in the full force, then it jumps from one idea to the next, always finding new ideas. For example, when I was a member of a Toastmasters club, I would get the idea, and would start thinking about it, and I would quickly get an idea, how to improve it, or get another idea and then an idea about how to combine it and in the end, I might still be getting these small ideas, but I would have no clue where it would lead me.
I like to imagine it like a small child, that is impressed by everything and wants to know more, but constantly jumps from one idea to the next and so on. Or maybe like a rabbit, jumping around the grass, or like a bee, going from the flower to flower.
That is also why, compared to the Ni thinkers, my ideas just seems so... shallow and unfocused.
Ni is a lot different. I remember one instance very well, where I used Ni. I got an idea, and this idea solved everything. There was that feeling of confidence and certainty, that I otherwise rarely experience. It was like the mulling of the problem in the subconscious mind (as well as conscious mind) have found some deep connections and then everything makes sense. I wonder if this is the real Aha moment that people experience.
It is hard to describe the feeling, the main reason not being that it was that profound, but because I could only describe as the contrast to my usual feeling of Ne, and they are so different that I don't really have words. It was like I was focused, that I was more attuned to the outside world and not trapped inside my head, that I actually noticed where I was. I still remember which parking garage was I seeing at the time. It was like there was no more nervous energy that is normally present.
I mean, for me it was something completely new, but I guess for people that use Ni in everyday life is seems normal. Which is why I found phenomenology that interesting, but also so frustrating to research with.
One of the differences that I noticed is also the range of the topics of interest. The Ne types are much more likely to have way too many topics of interest and not enough time for everything. On the other side, Ni types are much more likely to have a couple of interests, in which they are specialists.
Reading now through the text, I am not sure that I have managed to capture the essence of the difference, but it can maybe serve somebody as the reference for their own thinking or maybe my future one.