Direct-Attached Storage (DAS) Stands for "Direct Attached Storage." DAS refers to any storage device connected directly to a computer. Examples include HDDs, SSDs, and optical drives. While DAS can refer to internal storage devices, it is most often describes external devices, such as an external hard drive. The term "DAS" was created to differentiate between network-attached storage (NAS) and direct-attached storage. Before NAS and storage area networks (SANs) were available, direct-att...