Just want to share the difference between USB and Flash Drives.

USB (Universal Serial Bus)

In information technology, Universal Serial Bus (USB) is a serial bus standard to interface devices to a host computer. USB was designed to allow many peripherals to be connected using a single standardized interface socket and to improve the plug-and-play capabilities by allowing hot swapping, that is, by allowing devices to be connected and disconnected without rebooting the computer or turning off the device. Other convenient features include providing power to low-consumption devices without the need for an external power supply and allowing many devices to be used without requiring manufacturer specific, individual device drivers to be installed.

Source: Wikipedia

Flash Drive

USB flash drives are compact file storage devices to save your information externally. Flash drives are about the size of a disposable lighter and can be conveniently worn around your neck or attached to your keychain. The end of the flash drive is inserted into the USB port on the computer. Once attached to the computer, they operate in much the same way as floppy drives, but have capacities currently in the range of up to 2 gigabytes.

Source: About.com