Adding nodes to your existing network of knowledge is learning. Memorization is making the nodes persistent. Both are important, but they're not equivalent. You need to do both.
You can learn without memorization (you can learn a lot and forget everything you've learned by the next day). You can memorize without learning the subject matter (for example, you can memorize a counting song in Mandarin Chinese without knowing that what you've memorized are numbers).
Flashcards can be used for learning, but they are optimized for memorization. We shouldn't expect them to be the best tool for learning, because that's not what they're designed for. One might get better results learning from another resource, and then using flashcards to memorize the concepts they've learned.
Understanding is efficiently arranging and coordinating those nodes in an efficient path for most situations
Wisdom is knowing in which contexts to actually apply that path of nodes
Tacit knowledge is similar to wisdom just it generally lacks memorisation
There's not a perfect mapping in English between Memorisation, Understanding and Wisdom and their most pragmatic corresponding analogues in nature, but I have found this distinction between terms useful in the whole memorisation v understanding debate