Stands for "External Serial Advanced Technology Attachment." eSATA is a variation of the SATA interface that supports external storage devices. It was standardized in 2004 and uses the same pins and same protocols as internal SATA. However, it provides a slightly different, more rugged connector. The eSATA standard also supports a cable length of two meters compared to the one meter cable length supported by SATA.
Since eSATA uses the same protocols as SATA, an eSATA drive offers the same high-speed data transfer rates as and internal SATA drive. For example, an eSATA 3.0 drive can transfer data at 6 Gbps or 4.8 Gbps, taking into account the data encoding process. This is significantly faster than Firewire 800 (800 Mbps) and USB 2.0 (480 Mbps) and is on par with USB 3.0 (5 Gbps).
Because eSATA offers such fast transfer rates, it has been a popular external hard drive interface used by video editors, audio producers, and other media professionals. While eSATA is one of the fastest interfaces available, it is surpassed by both Thunderbolt (10 Gbps) and Thunderbolt 2.0 (20 Gbps), which are alternatives to eSATA.
Unlike Firewire, USB, and Thunderbolt, the eSATA interface does not provide power to connected devices. Therefore, all drives connected via eSATA must include a separate power connector to provide electricity to the device. A variation of eSATA, called eSATAp or eSATA USB Hybrid Port (EUHP), combines four USB pins and two 12-volt power pins into the eSATA connector. An eSATAp port supports both eSATA and USB connectors. It allows connected devices to draw power from the computer's power supply, eliminating the need for a separate power cable.