What is a 'flash drive' ?

Thanks ClubMan! I am still having difficulty synchronising my laptop internet access with my desk p.c. When I try to reinstall AOL on the laptop the WinInstal Wizard gets to a certain point then tells me it "can't detect flash-drive". This is usually when E-drive is identified in the menu-window. I can't understand what it's searching for as the AOL installation CD is in the CD-drive. Both my desktop and laptop are SONY and I've found their website and aftersales support timeconsuming and ultimately useless (snobby lot!)
 
What do you mean by "synchronising" your laptop and desktop internet access? What applications/utilities are you using for this? What exactly are you trying to do? Do you use a flash drive at all or is that error spurious in this situation?