Direct memory access is a feature of many computer systems that allows certain hardware subsystems to access main system memory independently of the central processing unit.
Motherboard of a NeXTcube computer (1990). The two large integrated circuits below the middle of the image are the DMA controller (left) and - unusual - an extra dedicated DMA controller (right) for the magneto-optical disc used instead of a hard disk drive in the first series of this computer model.