Difference External hard disk and Memory card?1 year ago - 1 answers
External Hard Disk's in general contain two parts. the Storage Disk and a controller. The Storage disk up until recently has always been a moving part mechanism like a normal computer hard drive, varying in size and speed. The controller is the interface between the External Disk and being seen by the Computer. These are usually, USB2.0 or USB3.0. E-Sata and Firewire are also used, but less common now due to USB 3.0's Speed benefits.
A memory card is a single static bit of hardware. It doesnt require a controller as such and it contains no moving parts. The controller part is handled by your media / memory card reader. This is why Memory Cards are so small. they dont require much hardware, just a rom chip to store data.
Now you can buy a USB3.0 Solid State Hard drive. no moving parts, but still requires the controller.
Source(s):1 year ago