Okay kiddo, so you know how when you go to school, you learn about lots of different subjects like math, science, and reading? Well, when someone wants to learn a LOT about one specific subject, they can go to school for even longer and get something called a PhD.
Now, some grown-ups really like learning about how businesses work and how people can be good leaders. That is what management is all about! So, when someone goes to school to get a PhD in management, they spend a really long time (sometimes up to 5 years or more!) studying all the different parts of how to run a company, like how to make decisions, how to motivate people, and how to make sure the business makes money.
This isn't an easy thing to do! To get a PhD in management, the grown-ups have to do a lot of reading and writing, and also conduct their own special experiments and research. They have to write a really long paper (called a dissertation) at the end, and then they have to talk about it to a bunch of other grown-ups who know a lot about management.
So, getting a PhD in management is kind of like becoming a superhero of running businesses. It takes a LOT of work, but it's worth it if you want to be really good at helping companies be successful!