An internal hard drive is built into the computer, while an external hard drive is connected to the computer via an external port (e.g. USB or Firewire).
The Solid State Drive (SSD) is a flash memory and normally smaller in size and storage (GB) in comparison to the Hard Disc Drive (HDD). A hybrid is a combination of a SSD and a HDD.
The physical size of the disk.
|Hard Drive Size
The amount of data that you can store in your drive, the size of the hard drive is measured in gigabytes (GB).
Indicates the maximum number of revolutions per minute (RPM), that is how many times the disk will rotate in one minute. The higher the RPM the better the performance.
This is the speed of which the interface can transfer information. For example, USB 2.0 has 60MB/s transfer rate. ATA 133 has 133MB/s. SATA150 has 150MB/s. The speed is given in Megabytes.
USB 2.0 The standard before USB 3.0. Has a data transfer speed at 480 megabit per second (Mbps).
USB 3.0 Is faster (625 Mbps) and more power efficient than USB 2.0, as well as backward compatible (meaning it works with older devices with older USB ports) but will then work at the same speed as the device.
USB 3.1 The successor to USB 3.0 and is more powerful and has a transfer speed that is twice as fast (10 Gbps).
USB Type-C A new type of port that is desgined for a reversible plug, is compatible with type A with an adapter or access cable.
|USB 2.0, USB 3.0|
If the unit is powered by the USB-port alone, which is common for portable external hard drives.