The Avanced Host Controller Interface (AHCI) is a hardware mechanism that allows software to communicate with Serial ATA (SATA) devices (such as host bus adapters) that are designed to offer features not offered by Parallel ATA (PATA) controllers, such as hot-plugging and native command queuing. The specification details a system memory structure for computer hardware vendors in order to transfer data between system memory and the device. As of July 2007, the current version of the specification is v1.2.