e SATA is the name of the standard for external SATA. The standard is the same as for the SATA that you normally use to connect the hard disks inside the computer, but the e SATA variant gives you the option of connecting units externally, e.g. external hard disks. This means that an external hard disk can use the SATA default & its high speed rather than e.g. being connected via the slower USB (Universal Serial Bus) standard. With this cable you can connect an e SATA unit to the e SATA port in your computer.