Well, according to the most recent highly scientific data from Wikipedia, it is still pretty hard to figure out what exactly constitutes pudding. However, there are a couple of important points to know:
When prepared correctly, pudding is food.
You probably have a different idea of what pudding is depending upon whether you live in the Commonwealth of Nations or not.
In the past, pudding was often a savory food such as haggis (a sheep's heart, liver, and lungs mixed with other stuff, delightfully cooked and served in the deceased animal's stomach).
In modern times, pudding normally means a dessert food.
Pudding can be one of two types: "baked, steamed, and broiled pudding" or "creamy pudding."
Check out what Wikipedia has to say about pudding at https://en.wikipedia.org/wiki/Pudding. Then, after you've gone down the three hour Wikipedia rabbit hole, come back and let us know what you found out! We gave up reading after the first couple of pages.
Either way is fine.