What it Means:
It has been years since the first universal serial bus (USB) device appeared to offer simple plug-and-play convenience. Yet, confusing names used to describe the technology are still around, giving dishonest vendors a chance to sell users a dud.
Even today, u may find MP3 players or flash memory drives sold as USB 2.0, Hi-Speed USB, or Full-Speed USB devices.
Confused? The technology basically when through 3 important updates: USB 1.0 (sometimes called Low-speed USB) offers up to 1.5 Mbps (megabits per second) transfer speeds; USB 1.1 (known as Full-Speed USB) offers 480Mbps.
If u r shopping for a flash memory drive or MP3 player, go for one that is certified Hi-Speed USB, as it offers the fastest speeds (480Mbps). Avoid a device with a better-sounding "Full-speed USB" label which actually offers significantly slower speeds (12Mbps)
Some vendors will claim their flash drive is "USB 2.0 compatible". The point ot remember: USB devices are all compatible with one another, what matters is the speed at which the data is transferred.
If u buy a "USB 2.0 compatible" flash memory drive, you may just end up with a USB 1.0 or 1.1 device. Sure, it will work when you plug it to a USB 2.0 port on your PC, but u get slower speeds when u copy files over.
Buy a device that is certified Hi-Speed USB. Anything slower is simply called a USB device.