Selected Music list.
SHUFFLE REPEAT —A Play Mode that randomly plays tracks from the Selected Music List repeatedly.
USB —Universal Serial Bus. A moderately high-speed input/output technology for "hot swap" data transfers, meaning that you can connect or disconnect a USB device without turning off your computer. Your Dell DJ Ditty uses the newer USB 2.0 standard that allows for higher speed transfers than USB 1.1.
WMA —Windows Media Audio. This is the standard used by Windows Media. Your Dell DJ Ditty can play tracks in this format, as well as MP3.