Well, there can be a lot to be understood in why something is defined the way it is. For example, a red-black tree is defined the way it is because it's a pretty simple structural way to force the tree to be "pretty well balanced". Why does it force that?
You're going for too big cards again. A single card doesn't need to answer absolutely everything there is about a red black tree. You want to ask about a single aspect of it per card.
The definition is "what is it?". There is nothing to understand here. It could be taught to a parrot or child to repeat this information.
What you're mentioning is a bunch of cards on top of that: how does a red black tree stay balanced on insertions? When is the self-balancing property of red black trees useful? When is it not? Etc etc.
You cannot answer this if you mistake a red black tree for another tree for example. It's essentially vocabulary.
Another one would be notations: what's the symbol for a cross product? Again, nothing to understand, but you must know it to work on actual math problems involving cross products.
I know that - I wrote the article which is the subject of this thread ;) I took you to be arguing that Anki should be used to learn without understanding.
