The CPUs are also called processors.
It is the active part of the computer, which adds numbers, tests numbers, signals I/O devices to activate, and so on.
The processor logically comprises two main components: datapath and control, the respective brawn and brain of the processor.
The datapath performs the arithmetic operations, and control tells the datapath, memory, and I/O devices according to the instructions of the program.
The figures on the right side shows the components of the Apple iPad 2 A1395.
The figures below show the iPad 2 logic board (main PCB, Printed Circuit Board), the Apple A5 chip, and the processor IC inside the A5 package.
The main memory of the iPad 2 includes 512 MB of DRAM inside the A5 package.
The A5 has two identical ARM processors that run at 1 GHz and a PowerVR grahpical processor unit (GPU) with four datapaths.
The interfaces to main memory are on the left and bottom side.