Isolated point

An isolated point is like a lonely island. Think of all the numbers as water in a big ocean. Most of the numbers have lots of other numbers around them, like schools of fish swimming together. But some numbers are like tiny islands, all alone by themselves. We call these numbers isolated points. They are special because they don't have any other numbers close to them. Just like a lonely island in the middle of the ocean doesn't have any other land around it. So, an isolated point is a special number that doesn't have any other numbers near it.