Definition - What does Android Fragmentation mean?
Techopedia explains Android Fragmentation
Android device manufacturers tend to customize the Android OS to stand out in the Android marketplace. Levels of variation range from differences in device hardware, such as display resolution and size, to modified Android application programming interfaces (API). Combined with frequent Android OS upgrades, these variations have amplified the fragmentation problem for most developers.
Google's stance is that fragmentation is not a serious issue, as the term has not been clearly defined. However, Google has released an Android compatibility program to help address application compatibility issues between devices. This program filters suitable devices that can gain access to applications and restricts Android market access to devices with altered Android APIs.
Nevertheless, the Android compatibility program does not resolve interoperability issues of applications made for particular devices, meaning that applications require tweaking prior to release across multiple devices.