ARM is the name given to microprocessor architecture developed and licenses by ARM Holdings.
ARM processors are at the core of the vast majority of smartphones and tablet PCs in the world as of July 2011. The microprocessors and microcontrollers are also used in embedded systems across industries. It is the most widely used 32.-bit reduced instruction set ISA in the world.
The technology can be licensed by other firms, and ARM Holdings has a long list of licensees for its technology. ARM processors drive most portable consumer electronics, such as mobile phones, PDAs, digital media players and so on.
Apple Inc.'s A4 and A5 microprocessors that power the iPad and iPhone models on the market are based on ARM technology.
The low power consumption and simple instruction set are the reasons why the ARM architecture is so popular in the area, but Intel Corporation plans to catch up with ARM and get its technology more into the market.