ARM NEON technology is the implementation of the Advanced SIMD architecture extension. It is a 64 and 128-bit hybrid SIMD technology targeted at advanced media and signal processing applications and embedded processors.
NEON technology is implemented as part of the ARM core, but has its own execution pipelines and a register bank that is distinct from the ARM core register bank.
NEON instructions are available in both ARM and Thumb code.
Not all ARM processors support NEON technology. In particular, there is no NEON support for architectures before ARMv7.