But how? Like, technically what makes the difference there?
AMD's definition of a "core" is different from intel's. You can get a short explanation from
here. Simply put though, due to the way the specific architectures are designed between chips, intel has a higher rate of instructions per clock cycle (IPC) than amd processors. This means that an Intel processor can get a lot more done in a single clock cycle, eliminating the need for a high clock speed.
In terms of intel's hierarchy for the most part, pentiums are 2 cores that can schedule 1 thread each, i3s have 2 cores that can schedule 2 threads at once, i5s have 4 cores that can schedule 1 thread at once, and i7s have 4 cores that can schedule 2 threads at once. Obviously there are exceptions for laptop processors and for high end 6-core offerings like the i7-4960X
