The main difference between the two processors is in their architecture and instruction set. The Cortex A9 processor is a Reduced Instruction Set based Computer (RISC) (ARM Inc.) while the Intel core series processors are Complex Instruction Set based Computer (CISC) (Intel Corporation). This means that there is a fundamental difference in how they execute instructions and the instruction sets that they have. The main aim of a CISC based processor (Core series) is to get a task done in as few lines of assembly language as possible. Hence, these processors have an instruction set in which each instruction is capable of performing several task in one go. Thus these instructions can take multiple clock cycles to complete. On the other hand, RISC based processor (Cortex A9) have an instruction set that consists of only simple instructions that take only a single clock cycle to complete. Thus they complete only a single task. Hence, the Cortex A9 processor may take a higher number of instructions than a core series processor to perform the same task. Although it is important to mention here that due to simplicity of their instruction set, Cortex A9 executes instructions much more quickly then a Core series processor (Roberts). Both Cortex A9 as well as Core series processor make use of multi-processing.