The acronym stands for 'Serial Advanced Technology Attachment' and is a computer interface employed for connecting standard ATA hard drives to a computer motherboard.
The SATA interface supersedes the PATA (parallel ATA) interface which has been used since the 1980s. A variant of the SATA interface, called eSATA (with the 'e' standing for 'external'), permits the connection of external hard drives. It uses a slightly different connector but is otherwise a very similar interface.