The difference between comprehension and understanding is a very fine line with the basic meaning of each term broadly overlapping.  However there is some subtlety to be applied when using these terms.

I would highlight this by noting, true comprehension requires much more than just  understanding.   Comprehension is generally broader and more holistic.

While understanding is at it’s core, comprehension includes the ability to conceptualize the broader context.  Fitting the various pieces together to form a broader and greater understanding, comprehension is really the next level.

Subjective

Understanding contains a subjective component.  I understand is all about you.  Your understanding might not match that of others but if not confusion can certainly arise.

Comprehension implies the broader context of taking others views into account, i.e., the bigger picture and translating this to a universal meaning that is not self centric.

Piecing together all the information rather than focus on a single point of understanding is the only way to be in a position to truly comprehend the situation.

Avoid Misconception

Understanding based on your own personal conception is common.  It is the baseline and how the majority of us develop conclusions.  Taking the time to fully comprehend can lead to avoidance of misunderstanding.

This is not a silver bullet.  Believing you have full comprehension in a particular circumstance does not mean that is so, validation is still needed.  Take the time to build a fact based objective foundation.

Working to fully comprehend both implies and requires looking more broadly and the situation and combining individual understanding into a cohesive whole.