Okay kiddo, so Mittag-Leffler's theorem is like a magic trick for math. It helps us find a special kind of function called a meromorphic function.
Now, don't get scared with the big name. A meromorphic function is just like a regular function, but it might have some places where it acts a little weird. It has little holes in it, kind of like Swiss cheese.
The Mittag-Leffler's theorem helps us fill in those holes. It tells us that we can find a bunch of special functions called partial fractions that will fill in those holes perfectly.
Think of the meromorphic function like a pizza with some missing slices. The Mittag-Leffler's theorem is like having a bunch of extra pizza slices that you can put in those missing spots.
So, with the help of Mittag-Leffler's theorem, we can now have a complete and perfect pizza...I mean, meromorphic function. Hope that makes sense!