The U.S. Patent Office has granted Apple a patent for the architecture for Systems-on-chip (SOC).What that effectively means is that all the circuitry integral to a computing device, like the processor and memory, will be on a single microchip. In more traditional layouts, each component is a distinct thing pressed onto a circuit board. The memory, the processor and whatever else are their own separate chips.
Effectively these SOCs allow for the performance in a greatly reduced space. It is an optimal solution for mobile devices. The A6X in the fourth-generation iPad is one such SOC already in production.