These memory devices are compatible with both Mac and Windows PC. Plug and play functionality offers system compatibility and offers extensive storage options and portable design for the consumer. These storage devices come in varying storage capacities, but they all connect to a computer either by USB, eSATA, or wirelessly. Some advanced disks may require an AC connection to derive power on their own.
Standard Hard drives draw power from their data source cable, which comes from the system itself. An external hard drive is just a storage device that is connected to your computer on the outside.