What Is a USB?
USB stands for Universal Serial Bus. Essentially, it is the common interface that enables a wide range of devices to communicate with some kind of host controller, thus making the process much easier than otherwise possible. With that said, some people sometimes use USB to refer to USB devices, with an excellent example being USB flash drives.
What Is a Flash Drive?
Flash drives are devices containing flash memory, thus enabling them to be used for both the storage and the transfer of data. As for flash memory, it is a kind of non-volatile memory, meaning memory that continues to retain its stored data even when it is no longer being supplied with power. This is in contrast with volatile memory, which need a constant supply of power for them to retain their stored data. Some people might be familiar with the use of flash memory in other contexts as well, with a particularly good example being SSDs. Besides this, it is interesting to note that flash memory is not a particularly new technology, though the considerable improvements that have been made over the course of decades are what have enabled it to become so popular in modern times.
What Is a Thumb Drive?
The term “thumb drive” is just another name for USB flash drives. Presumably, it came into existence because of the small size of such devices, which is one of their most useful characteristics. After all, it is much easier to carry a small flash drive around compared to a full-sized hard drive.
Which Is Which?
Summed up, flash drives and thumb drives are different names for the same devices. Meanwhile, USB is the interface that enables them to be used with such a wide range of computers, though it isn’t unknown for USB to be used as shorthand for USB flash drives. Due to this, it can be important to distinguish between these two potential meanings for maximum clarity and comprehension.