What does maximum depth level mean?

Question

I recently read this article, what are you saying:

The maximum depth level of a document is 100.

Which left me with the following doubt:

What the author is saying with depth level of a document?

Answer 1

Documentation.

Mongodb works with document nesting, right? You can go putting "sub-documents" inside each other. It’s like they’re tags XML/HTML, you put one inside the other. When you put a document/data inside another, this is a level. When you put another document inside this one that you just put in, it’s another level, and so on, each one inside the other is adding a level.

If you think of one box inside another, you can put 100 boxes. Of course, if you’re placing two boxes next to each other inside another box, you’re not adding two levels, the two are on the same level. There is a level with only 2 different elements, only when one goes inside the other forming a level. The same could be said for folders, directories, etc., only that they are documents.