eSATA is a version of SATA which is used to connect external drives. Its plugs are more robust, and its cables are more rugged. In this market, SATA competes with other standards, such as USB or Firewire. Many external drives are standard SATA drives in an external case. To be able to communicate over USB or Firewire, an extra electronic board is needed. This board translates between SATA and the external interface. When eSATA is used, no translation is necessary. Using USB or Firewire may have other benefits though.