Etty Hillesum was a Dutch Jewish young woman who wrote diaries in Amsterdam under Nazi occupation. Her diaries focus on deep psychological and philosophical insights, morality and how to remain human under persecution, including a strong focus on radical pacifism and love. She refused to live in hiding, and volunteered to be sent to the camps during the first deportations, where she worked as a nurse until her death.
Anne Frank, on the other hand, was a 13-years-old teenager who wrote her diaries while hiding with her family, focusing on coming-of-age issues and the hardships of isolation.