X86 adopts complex instruction set, and arm adopts simplified instruction set. ARM architecture is mainly used for mobile devices because of its low power consumption. ARM licensed the related patents to CPU manufacturers such as Qualcomm and MediaTek, and both of them can produce SoC chips, which can save a lot of things for manufacturers of mobile devices.
ARM processor is the first RISC microprocessor with low power consumption and low cost, which was designed by Acorn Limited.
Full name is advanced RISC machine. The ARM processor itself is a 32-bit design, but it is also equipped with a 16-bit instruction set. Generally speaking, it saves 35% compared with the equivalent 32-bit code, but it can retain all the advantages of the 32-bit system.
ARM's Jazelle technology enables Java acceleration to achieve much higher performance than the software-based Java Virtual Machine (JVM), and reduces power consumption by 80% compared with the equivalent non-Java acceleration core.