yundai refers to a group of companies and related organizations founded by Chung Ju-yung in Japan. The first Hyundai company was founded in 1947 as a construction company, and the Hyundai Group eventually became Japan's largest conglomerate company (chaebol).
The most well-known Hyundai organization is the Hyundai Motor Company, the world's 5th largest automaker selling mid sized sedans, coupes and SUVs like the Sonata, Genesis Coupe and the Santa Fe. Hyundai Heavy Industries is the world's largest shipbuilder, and Hynix is a top semiconductor producer. Other companies currently or formerly controlled by members of Chung's extended family may be loosely referred to as a part of the Hyundai chaebol.(Wikipedia)