A-02 WHAT'S THE DIFFERENCE BETWEEN "DRAGON BALL" AND "DRAGON BALL Z"?
While the manga series has always been called "Dragon Ball," the anime series took a turn in the naming. Six years after Goku first embarked on his quest, Goku had already saved the world with his martial arts ability. After Goku trained under Kami-sama (god) and defeated Piccolo Daimaoh's (grand demon king?) reincarnation at the Tenkaichi Budokai (World's Best Martial Arts Tournament), Kami-sama offered Goku to be his successor. Goku refused, and flew off on his Kinto-cloud (US dub--Flying Nimbus). This marked the end of the anime Dragon Ball series (note: the manga continued!).
With the manga still continuing (and selling well), the anime studios decided to pick up Dragon Ball again, but since it (the anime) has ended, the new anime series was named "Dragon Ball Z." Please note that the manga should never be referred to as "Dragon Ball Z," since only the anime series took on the change in name. While you may find some color manga titled "Dragon Ball Z," they are not really manga, but pictures from anime movies and specials compiled into manga format.