Some things are understood immediately. Others take time and effort. The difference between self-evident truths and truths that need to be deduced is comparable to the three intellectual virtues.
Understanding refers to self-evident truths.
The difference between wisdom and science lies in what they comprehend. There remains a connection between wisdom and science, especially when we consider sacred doctrine as a science. Science concerns itself with particular areas of truths. The object of sacred doctrine is God. Thus, wisdom comes from the study of the science of sacred doctrine.