Kernel Fisher discriminant analysis is like a teacher who helps you separate different types of things based on their similarities and differences.
Imagine you have a bunch of fruit and you want to separate them based on whether they are round or not. You can't simply use their size, color or texture because sometimes an apple can be small or big, red or green, smooth or bumpy.
So you ask the teacher to help you. The teacher takes a look at the fruit and decides to use a special method where they draw a line right in the middle of the fruit that separates the round ones from the ones that are not round. They do this by looking at how the fruit is shaped and finding the best line that can split them into two groups.
But there's a catch - some fruit are really hard to separate because they are too similar to each other. That's where Kernel Fisher discriminant analysis comes in. It's like the teacher uses a special ruler that can 'squish' the fruit and make them look different so they are easier to separate.
The ruler is like a special mathematical formula that takes the fruit and 'squishes' them in a special way so that they become easier to separate into different groups. The teacher uses this ruler to help them find the best line that separates round fruit from those that are not round.
In the end, you have all your fruit separated into round and not-round groups, and you can use this method to separate other types of things as well. That's what Kernel Fisher discriminant analysis does - it separates things into different groups using a special mathematical formula that makes things that are hard to tell apart easier to distinguish.