A DMA Controller (Direct Memory Access Controller) is a hardware component that allows certain hardware subsystems to access the main system memory independently of the central processing unit (CPU). This enables efficient data transfer between devices, such as hard drives or network cards, and memory without burdening the CPU, which can continue executing other tasks. By using a DMA Controller, data transfers can occur in the background, improving overall system performance. It is particularly useful in applications that require high-speed data movement, such as video processing or large file transfers, where minimizing CPU involvement can lead to faster and more efficient operations.