An Arm processor is a type of central processing unit (CPU) that is based on the reduced instruction set computer (RISC) architecture. Arm Limited, the company behind the Arm processor, creates the core CPU components and licenses the intellectual property to partner organizations, who then build Arm-based chips to their specifications. Arm Limited does not directly manufacture or sell chips.

In the 1980s, Acorn Computers created the Arm processor. Until recently, the name Arm was used as an acronym, ARM, which stood for Acorn RISC Machine and then Advanced RISC Machine. Although the acronym is still widely used, Arm Limited refers to its processor technology solely as Arm.

Arm Limited develops 32-bit and 64-bit RISC multicore processor designs. The processors have a much simpler instruction set than Intel processors, which are based on the complex instruction set computing (CISC) architecture. The two types of processors also use different methods to improve performance and efficiency. For example, Intel optimizes performance through hardware, whereas Arm optimizes performance through software.