If you want to sell an application on the iPhone, you must do so through Apple's online store and you must get Apple's permission. Google is launching something called Android Market, a free-for-all site where anyone can create an application and post it online for others to download.
In techie circles this contrast is known as "the cathedral and the bazaar," based on an essay by a hacker named Eric Raymond in 1997. Raymond was writing about ways to create software, but the concept applies to the market as well. He argued that the old, hierarchical, highly controlled approach where development is controlled by a priesthood of experts (the cathedral) would be outpaced by the freewheeling open-source approach where anyone could contribute (the bazaar).
Dan Lyons
Newsweek