Direct Memory Access (DMA) is a feature of computer systems that allows certain hardware subsystems to access main system memory independently of the central processing unit (CPU) . DMA enables a computer to transfer data to and from devices with less CPU overhead. Without DMA, when a computers CPU receives data requests from an attached device, it becomes preoccupied with those requests and is unable to perform other operations during that time. With DMA, a CPU initiates a data transfer with an attached device and can still perform other operations while the data transfer is in progress. DMA channels send data between an attached peripheral device and the system memory. System resources such as the CPU, memory, attached I/O devices, and a DMA controller are connected through a bus line, which is also used for DMA channels. DMA can also be used for "memory to memory" copying or moving of data within memory. DMA is of interest in network-on-chip and in-memory computing architectures.

It is important to note that DMA can also refer to Designated Market Areas (DMAs), which are regions of the United States used to define television and radio markets. However, in the context of computer systems, DMA refers to the feature that allows hardware subsystems to access main system memory independently of the CPU.