Zeni

From Dragon Ball Wiki, the ''Dragon Ball'' encyclopedia

Zeni is a type of currency in the Dragon Ball series.

Zeni is also featured on many Dragonball Z Video Games such as the Budokai Series and the Tenkaichi Series. They can be found on the story mode of the game and winning a tournament in the World Tournament mode in order to buy techniques, items etc. in the game's shop. (alternatively, Zeni can also be earn by finishing runner-up after losing in the final)

According to Toriyama one zeni is equal to a yen (100 zeni=about 1 US dollar)