"Dragon Ball Z" is a Japanese anime series about a martial arts master named Goku, whereas "Naruto" is an anime about a young ninja named Naruto. Both "Dragon Ball Z" and "Naruto" are popular anime and manga series in Japan, but they have very different plots and settings.
"Dragon Ball Z" focuses on the adventures of Son Goku. Goku is a powerful warrior and martial arts master. Throughout the course of the series, he defends the Earth by fighting against powerful foes. His enemies include intergalactic fighters and conquerors, various monsters and even androids. The series focuses mostly on Goku's attempts to defend the Earth, as well as his relationships with other characters from Earth and outer space.
"Naruto" is an anime series that focuses on a young ninja named Naruto Uzumaki. Naruto seeks to become the Hokage, which is the most powerful ninja in a village. The series focuses on Naruto's life as he trains to become stronger. It also focuses on his relationships and rivalries with other ninjas, and the many struggles Naruto faces as he undergoes intense training missions.
Though "Naruto" and "Dragon Ball Z" have different plots, they are both popular and successful and explore similar themes.