DAT may refer to any of the following:
1. Short for Digital Audio Tape, DAT was originally developed by Hewlett Packard and Sony as a solution for backing up information on a computer or network. DAT drives and tapes are available in two primary formats, DDS (Digital Data Storage) and DataDAT. DDS drives come in three different types, DDS-1, DDS-2, and DDS-3.
2. A DAT can also be used to describe a PC file or file extension, dat being short for data. For a complete listing of computer file extensions, see our file name extensions index.
3. When referring to a virus protection program such as McAfee, DAT refers to the file used to update the virus protection software with the latest updates.
4. DAT is chat slang for that.