It determines the type of CPU the particular tablet has. Currently several competing models of CPUs are available on the market.
NVIDIA Tegra - the processors of this series have good graphics and processing performance as well as quite good energy efficiency indices. In any case, this is a strong competitor.
SnapDragon - this processor is highly energy efficiency, however, from the point of view of capacity it is more suitable for smartphones.
AMD Fusion - this processor comes from the environment of portable computers, therefore it has excellent performance as regards both graphics and processing, still the architecture of this processor unfortunately is intended only for the use in the Windows, Linux and other desktop computer environments.
Atom - Intel mobile processor with average capacity indices. Similar to AMD Fusion, for the time being it can be used only with the operating systems of desktop computers.
Apple A5 - specialised processor developed by Apple that can be found in iPad tablet computers only. From the capacity point of view - among the leaders.