DMA, direct memory access, is a technology which is used by certain devices in a computer to access the system's memory (RAM) directly, without having to utilise the CPU to manage the data transfer.

Direct memory access works by assigning a unique DMA channel to each DMA-enabled device in the system.

In older systems, running out of DMA channels was a real possibility, these days, however, there are less devices that require the use of a DMA channel. Some typical devices which still use the DMA system include certain keyboards, disk controllers, network cards and sound cards.

DMA can control the memory for as many clock cycles as is required for the process. It only needs to interrupt the processor at the start, and end of the data transfer, which significantly reduces the workload of the CPU.

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