Layers of Android

1. A Linux kernel that provides a foundational hardware abstraction layer, as well as core services such as process, memory, and filesystem management.
2. Prominent code libraries, like Browser technology, Database support ,Advanced graphics support,Audio and video media support, SSL
3. An array of managers that provide services for Activities and views,Windows, Location-based services, Telephony, Resources
4. The Android runtime : Core Java packages and Dalvik VM.