Understanding a concept means you get it. The meaning of understanding is a mental grasp : Both comprehension and understanding can be used to talk about someone's ability to understand something.
Exploring the Diverse Cultures of the Middle East
He noted bond's apparent lack of. Understanding implies abilities and dispositions with respect to an object. Or about how something works:
How to use understanding in a sentence.
Knowledge about a subject, situation, etc. Understanding is a relation between the knower and an object of understanding. Comprehension usually used with of. Your understanding might be that your mother will always drive you to school if you miss the bus.