Although the Sega Master System had proved a success in South America and Europe, it failed to ignite much interest in the North American or Japanese markets, which by the mid-to-late 80s were both dominated by Nintendo with 95% and 92% market shares respectively. Hoping to dramatically increase their share, Sega set about creating a new machine that would be at least as powerful as the then most impressive hardware on the market - the 16-bit Commodore Amiga and the Atari ST home computers.
Since the System 16 arcade games that Sega was making were very popular, Hayao Nakayama, Sega's CEO at the time, decided to make their new home system a 16-bit one. The final design worked great and fit in well with Sega's three new arcade boards; the Mega-Tech, Mega Play, and the System C. Any arcade game made for these systems could easily, and thus rapidly, be made to work on the new console (a process known as porting).
The first name Sega thought of for their console was the MK-1601, but Sega decided to use "Sega Mega Drive" as the name. "Mega" had the connotation of superiority, and "Drive" had the connotation of speed and power. They went with that name for the Japanese, European, Asian, Australian and Brazilian versions of the console. The U.S. version went by the name Genesis due to a trademark dispute, while the South Korean versions were called Super Gam*Boy (삼성수퍼겜보이) and Super Aladdin Boy (transliterated from 수퍼알라딘보이; this was the Korean version of Mega Drive 2). Those consoles were licensed and distributed by Samsung.