A Direct Memory Access (DMA) controller is a dedicated hardware engine that facilitates autonomous high-throughput data transfers between system RAM and high-speed peripherals without continuous CPU intervention. By negotiating bus mastership via Hold Request (HOLD) and Hold Acknowledge (HLDA) handshakes, the DMA unit streams contiguous byte buffers using hardware address and counter registers. Offloading repetitive memory moves preserves core CPU clock cycles for primary execution threads.