If you don't know what it is, certainly don't turn it off!
DSC is traction control basically. Keeps your wheels from spinning excessively if 1 or more lose traction (wet conditions for example, or, throwing your car into your favorite onramp at 70mph might cause it to flash too..)
I'd not turn it off, unless you're doing times, and want to get a good launch. Or if you're a good driver, and like to steer with your rear.
<img src='http://22.214.171.124/coDataImages/p/Groups/12/12267/folders/124915/1454131newsig.jpg' border='0' alt='user posted image' />
<a href='http://seboc.com' target='_blank'><span style='font-size:8pt;line-height:100%'><span style='color
- Southeastern BMW Owners Club</span></span></span></a>