Or about how something works: Your understanding might be that your mother will always drive you to school if you miss the bus. The meaning of understanding is a mental grasp :
Special test not so special in diagnosing shoulder pathology
Understanding is a relation between the knower and an object of understanding. Comprehension usually used with of. Knowledge about a subject, situation, etc.
How to use understanding in a sentence.
Understanding implies abilities and dispositions with respect to an object. Both comprehension and understanding can be used to talk about someone's ability to understand something. He noted bond's apparent lack of. Understanding a concept means you get it.