ARM architecture

ARM architecture is a computer CPU architecture used in computers of all sizes up to supercomputers; commonly used in embedded systems and mobile devices such as cell phones, tablet computers, and handheld game consoles such as the Game Boy Advance. ARM CPUs use very little electricity and produce very little heat. Most ARM CPUs run on battery power and don't need a cooling fan. The Linux operating system is used most on ARM CPUs. 
In 2013 ARM was the world's most popular 32-bit CPU architecture. Since then, production has increased to millions per day. 64-bit ARM, which allows for addressing memory greater than 3.8GB, has been available since then and is used in most modern smartphones.