When you look at the CPU in your PC, you're actually looking at the entire CPU package. The 'core' is the small layer of silicon inside the package that does the 'computing'. Measured in nanometers (nm).
negative to most of the above, come on guys,I know most of you are gamers but sheesh
90nm or 130nm refers to the process used in nanometers which basically is the thickness of the pathways of the connections between transistors in the CPU, the smaller that number is, the more transistors they can put inside a given space on the silicon die, but it has a side effect, while smaller pathways waste less energy due to resistance(making less heat),they also leak more current and have a lower threshold to higher voltages, they bleed a lot of energy at higher voltages creating even more heat.
The "core" is the basic part of the CPU that handles insructions, in some cases it may be considered the entire CPU, these days though like with AMD they also integrate other things on the CPU die like a memory controller and cache memory which technically arent really part of the core.When they make these chips they often make several models and many parts of them stay unchanged from model to model, like cache memory or the memory controller.Which is why the term "core" has been created, CPU's have become modular, where as in the past they only had a few basic parts and most of the other functions were handled by support chips on the motherboard.