(Serial ATA) A serial version of the ATA (IDE) interface, which has been the de facto standard hard disk interface for desktop PCs for more than two decades. The original Parallel ATA (PATA) interface was launched in 1986. SATA was introduced in 2002 at significantly higher speed, transferring data in each direction at 1.5 Gbps. A year later, SATA II increased speed to 3 Gbps.

SATA provides a point-to-point channel between motherboard and drive rather than the master-slave architecture in the parallel technology (see IDE).

Smaller Cables and Connectors
SATA uses a four-wire shielded cable up to one meter in length compared to the wide, flat, 18" PATA cables. SATA cables and connectors are considerably smaller than their PATA counterpart and take up a lot less space in the case.

eSATA
SATA defines only internal drives, but eSATA (External SATA) enables them to reside in their own housing outside the computer and be plugged in as required. Providing an external, hot swappable drive solution similar to USB, SATA offers much higher speeds than the USB bus.

Cables up to two meters long attach eSATA drives to the computer either via an eSATA PCI card or directly to the internal SATA socket on the motherboard. A short cable extends the motherboard socket to the back of the computer. Designed for thousands of insertions, eSATA plugs and sockets are more rugged than internal SATA connectors. See IDE and SAS.