There are external and internal conflicts in The Notebook by Nicholas Sparks.

One conflict is character vs. character, as Allie and Noah are up against Allie's parents. Allie's parents do not approve of her relationship with Noah. Her mother, Anne, hides the letters that Noah sends Allie, which causes further conflicts. Noah thinks that Allie is choosing to not respond to him, while Allie believes Noah is not writing to her.

Allie faces an internal conflict when she sees the newspaper article about Noah restoring the house. She wonders if Noah forgot about her or if he ever really cared for her. She wrestles with these unsettled feelings for him and is conflicted because she is about to be married to another man. Allie goes to see Noah in New Bern in an attempt to get some closure but ends up feeling even more conflicted, as she must choose between Noah and Lon.

Typically "character vs. self" describes the internal conflict one feels when determining what is right vs. wrong or has to choose between mixed emotions (as Allie experiences in the above example). This book has an interesting character vs. self conflict in the sense that as an eighty-year-old woman, Allie is battling against her body and deteriorating mind. She struggles to remember, at times not recognizing Noah but other times calling him by name.

This is a great question and I would say that there are three main conflicts in the book.

First, the most obvious conflict is based on class. Noah is a great man, but he does not come from money and privilege. This is a point of contention, because Allison does come from money. Moreover, her mother is very keen on keeping Allison from Noah. She want to protect her by allowing her to marry within their social class. This socio-economic barrier is one of the strongest in the work.

Second, there is also a family conflict. As was intimated above Allison's mother is only trying to look at for her daughter. However, she play a huge role, because she does all in her power to keep Noah and Allison at arms length; she almost succeeds.

Finally, there is a biological or physical conflict. In Allison's later years, she is not able to remember Noah and their life together. So, Noah tries his best to win her over every time with the reading of a notebook.