Okay kiddo, let's imagine you have a toy box with lots of toy blocks in it. You can count them and see that there are 10 blocks. But what if I give you more toy blocks and say you can keep getting more and more of them, without ever running out? That would mean you have an infinite number of toy blocks!
In the same way, there are some fancy math things called functions that can have infinite blocks too. They're called infinite-dimensional holomorphic functions. Just like you can play with lots of toy blocks and make different shapes and patterns, mathematicians can play with these functions and do cool things with them too.
But what makes these holomorphic functions special is that they have certain rules they have to follow, just like how you have to follow the rule of not throwing blocks at your little sister. One of these rules is that the function has to be something called "analytic," which means it can be written out as a special type of equation.
Another rule is that the function has to be "holomorphic," which means it has to be really smooth and nice. Think of it like how you always have to be nice to your friends and not take their toys away.
Overall, these infinite-dimensional holomorphic functions might seem a bit complicated, but they're actually just really special types of math toy blocks that mathematicians can play with in cool ways!