DAT is natively a digital tape format for audio files. Designed by Sony in the late 1980s, it was created to replace traditional audio tapes.
HP and Sony are partnering to define the DDS standard for Digital Data Storage resulting from this technology. The physical mechanism is the same, but the encoding is different.
This format initially competes mainly with DLT and LTO systems.
The DAT format uses two different tape formats, the most common are DDS, and DataDAT.
The DDS originally uses 3.8 mm tapes, and the most recent formats (DAT 160 and DAT 320) uses 8 mm tapes.