Kaiba Corporation is the company owned by Seto Kaiba, founded by his adopted father Gozaburo Kaiba. It is the source of much conflict, as series antagonists are often attempting hostile takeovers of the company.
According to the anime, KaibaCorp was previously a weapons company, until Seto converted it into a gaming company. It now produces shiny holographic and virtual reality gaming systems, apparently mostly for what were originally traditional, non-electronic games.
Seto Kaiba (CEO)
Mokuba Kaiba (Vice President)
Isono (Roland in the dub) (not clear)
Gozaburo Kaiba (Former CEO)
The Big Five (Board of Directors, removed from employ after Duelist Kingdom, due to attempted takeover)