The World of Dragon Ball Z is a 20 minutes OVA special made and released by FUNimation Entertainment in 2001. This special reviews the Dragon Ball series from the Emperor Pilaf/Tournament Saga up to early Androids Saga.
The World of Dragon Ball Z was a teaser in the Androids Saga VHS and DVD called "Dragon Ball Z: Androids - Dr. Gero". Two different dubs are used in this special: the SABAN dub and the 1995 Ocean Dub; this is because FUNimation Entertainment did not have the rights to the Saiyan Saga and early Namek Sagas until SABAN's dubbing rights for Dragon Ball Z ran out, a few years after the was OVA released.