What is the difference between a CPU core and a CPU thread? — The difference between a core and a thread is that separate cores have separate copies of (almost) all the hardware resources. The cores can run completely independently unless they are using the same resources–e.g., the connections to the outside - at the same time. Threads, on the other hand, share almost all of the processor’s resources. Intel’s implementation of threads has only separate registers for the threads and even that is limited, some registers are shared.