I come with a theoretical question related to the well-known STM32 blue pill, to be more specific, I don't know if the NVIC controller is a type of DMA. I would say that it is a DMA as long as it manages the interrupt requests, on the other hand, I haven't yet found any documentation according to which the NVIC could be categorized as a DMA.
No. The nested vector interrupt controller is not a DMA peripheral.
It is an interrupt controller. It manages interrupt requests. It cannot access memory directly because it is not a bus-master. It does tell the processor core which code to execute, but the code is fetched by the processor on the I-Code bus not by the NVIC itself.