Android is not locked into a single hardware ecosystem. Many prominent handset manufacturers, such as HTC, Motorola, Samsung, and LG, have jumped onto the Android bandwagon, and they offer a wide range of devices running Android. In addition to handsets, there are a slew of available tablet devices that build upon Android. Some key concepts are shared by all devices, though, which will make your life as game developer a little easier.
Among the things that will be discussed later in the section on that moving target, Compatibility, Google originally issued the following minimum hardware specifications. Virtually all available Android devices fulfill, and often significantly surpass, these recommendations: