Holomorphic discrete series representation is a fancy term used in math for a certain kind of way to represent numbers. Imagine you have a treasure chest (like a pirate's treasure) and inside there are many shiny gold coins, but they are all different sizes. In the same way, numbers can be represented in many different forms, and these different forms are called representations.
Now, let's focus on a special kind of representation called "holomorphic discrete series". Think of it like different shapes of treasure chests - some are round, some are square, and some have fancy decorations. Holomorphic discrete series representation is like a very special kind of treasure chest that is decorated with lots of shiny jewels - it's very beautiful and unique.
One important thing about this kind of representation is that it is very precise - it gives you very specific information about the numbers you are working with. It's like having a special map that shows you exactly where all the treasure in the chest is hidden, so you can find it easily.
But, just like with real treasure chests, not everyone can open this kind of representation easily. It takes a lot of skill and knowledge to be able to work with holomorphic discrete series. But if you learn how to use it, it can help you solve very complicated math problems and even lead you to discover new things about numbers.