Video narration
You're copying a photo on your phone, and while it moves, you can still scroll or message. It's a useful analogy: a transfer doesn't have to keep the processor busy from start to finish. Direct Memory Access, or DMA, is a way for data to move between a device and memory without the CPU carrying every piece. The CPU still starts the job. It tells the DMA controller what data to move and where it should go. Then the handoff happens: the DMA controller moves the data between the device and memory, while the CPU turns back to other work. When the transfer is finished, it signals the CPU. The exact setup and completion signals vary from system to system, but the basic handoff is the same. Remember the point: DMA moves the data, so the CPU gets time back for the work you actually notice.