He had a better understanding of the terms than Nanette.
Explanation:
With Nanette, she only used a textbook definition. All she did was highlight the definitions she found in the textbook.
With Nathan, he didn't just stop at knowing the textbook definitions. He thought about its application in his life, relating each defined term to his personal life experiences. He then went the extra mile of relating them to other concepts in the text book.
This means he had a broad understanding of the terms both on a personal level and in relation to other concepts in the chapter. The way he processed and understood the terms will make him recall better in an essay exam.