The Sega Genesis also known as the Sega Mega Drive, was a video game console based on the Motorola 68000 processor. It used ROM cartridges for gameplay.
Sega Genesis ROM images generally have the extension .BIN although some roms are in a different format, These formats are harder to hack becuase of swapped bytes and other changes so they should be converted before use.
While the Sega Genesis has had mediocre RPGs (role-playing games), their sports and action games dominated the early half of the 1990s only to be succeeded by the Super NES when advancements in Nintendo's Mode 7 technology made rapid rotating possible in the year 1994. After that, Sega Genesis' sports games (especially American football) were sub-par compared to the Super NES sports games.