Game development is the software development process by which a video game is developed. Development is undertaken by a game developer , which may range from a single person to a large business. Mainstream games are normally funded by a publisher and take several years to develop.
Indie games can take less time and can be producedcheaply by individuals and small developers. The indiegame industry has seen arise in recent years with the growth of new online distribution systems and the mobile game market.
(Taken from: wikipedia)