Okay, so a doctor of commerce is like a really smart person who knows a lot about money and business. Just like how your teacher is really good at teaching you math, a doctor of commerce is really good at understanding how businesses work and how they make money.
To become a doctor of commerce, you have to study a lot in school for a really long time. You have to learn about things like accounting, finance, marketing, and economics. It's kind of like when you practice your ABC's over and over again until you know them perfectly – except with a doctor of commerce, they practice things like calculating how much money a company makes or deciding which products to sell.
People who become doctors of commerce can do a lot of different things with their knowledge. They can work for big companies or start their own businesses. They can even teach other people about money and business, just like your teacher teaches you about math.
So, that's what a doctor of commerce is! They're just really smart people who know a lot about money and business.