Android system safety inherited the design of Linux in
the design ideology, Android provided security, memory
management, process management, network management,
drive model and other core service in the kernel. The kernel
part is actually a abstract level between hardware abstraction
layer and other software group. In practice operation, each
Android application runs in its own process. Android system
applications are run in some low-level function such as
threads and low memory management; Android itself is a
separate operating and permission system. In the operating
system, each application runs with a unique system identity
(Linux user ID and group ID).