By and large, in the ways that I use the words "Insight" and "Wisdom," they're the same. Maybe one sounds better in certain contexts than the other. "Wisdom," of course, is a very common word, whereas "Insight" is not, so in that way, Insight might sound like something deeper. We may say we have, all of a sudden, understood an Insight; we've seen into something. We have, all of a sudden, understood a type of wisdom; we've seen into something. They can work the same sometimes, but, then again, English is a language where we can play and use different words that give slightly different emphases even though they basically mean the same thing. The Insight that we're getting is a type of Wisdom. The Wisdom that we get are Insights into whatever is wise. These words work back and forth.
For those of you who don't know, English as a language has the largest vocabulary in the world. From what I've heard, German is second, and they only have about 50% of the words English has. It's a huge amount of words that English uses. English people like to invent new words for everything. By contrast, Thai is a very simple language. In English, we have the words "airplane" and "pilot." What is a pilot? A pilot is a person who flies planes. The Thais have the word the "plane," but they don't have "pilot." They have "the person who flies planes." They put the words for "person" and "plane" together; they didn't invent a new word. This is a little example of what English has done.
What happens with this is that it gives us an ability to express ourselves on different levels in English that can be very subtle, and that are different to what many other languages can do. English can be more subtle. So, depending on you how use the word "Insight" or "Wisdom," it may be slightly more subtle than a general type of wisdom.
Regarding different levels or types of insight, watching a leaf and considering that everything is impermanent is on the mental level. We're reflecting. I think three levels of wisdom are listed in the scriptures. One is when you listen to or read something; that's wisdom that comes in from somebody else. The second is that we reflect about what we've seen, what we've heard, what we've tasted, what we've smelled, and so on. We reflect; this is the second type of wisdom or insight. The third type is that we know it, we absolutely know it. We don't have to reflect, though we might still say "ummm, everything is impermanent," but it comes from a knowing rather than a reflecting.
A little example of this is a little 3-year-old kid who Mommy and Daddy never allow in the kitchen because the stove is low, hot, and dangerous for the kid. While Mommy or Daddy's in the kitchen cooking, the little kid comes in and goes, "Can I play in here?" This time Mommy or Daddy reckons, "Well, the kid's old enough. Maybe it's okay." They say, "You can stay in here for now but be very careful of that. It's a stove and it's very hot." The kid has no idea what a stove is; they just heard the word for the first time. They also don't really know what "very hot" means so these are words that just go into their ears and right back out. They can't even reflect they upon what it might mean. Although they may know the word "hot," maybe they think they jump in a swimming pool or have a bath when they're hot. That's about all they can do with it.
Now, the kid sees the stove, and, you know, stoves usually have a glass window. They have dials. What do they look like? A TV. The kid gets interested in the stove because it looks like a TV. When Mommy or Daddy turns their back and starts chopping vegetables or something, the kid goes up to the stove and touches it and "Wheew!" It's hot and they burn themselves. At that moment, the kid has jumped from the level of understanding wisdom on the level of seeing and hearing. They didn't even get much reflection at all, but jumped straight down to the of knowing of what "a stove is hot" actually means. Often, this getting down to actually knowing something depends on really, truly experiencing the situation fully for what it is. So, in general, the scriptures talk about those three levels of wisdom or insight.