Which type of storage device is commonly referred to as a thumb drive?

A thumb drive is commonly referred to as a flash drive because it utilizes flash memory to store data. Flash drives are portable, compact, and can easily connect to computers via USB ports, making them highly convenient for transferring files. The term "thumb drive" is often derived from their small size, resembling a human thumb, and they have become synonymous with flash drives in everyday language.

In contrast, hard drives are larger storage devices typically used to store larger amounts of data permanently, while optical disks, such as CDs or DVDs, rely on laser technology to read and write data. SD cards, or Secure Digital cards, are also portable storage devices commonly used in cameras and smartphones but differ in form factor and connectivity. Therefore, the identification of the thumb drive with flash drive technology is accurate and reflects the common understanding and usage of these storage devices.