With global stock markets suddenly volatile again, investors might need a refresher on some of the terms being thrown around. First off, the markets didn't crash. While the 1,175 point drop Monday in the Dow Jones industrial average might sound like a collapse, the decline was less than 5 percent. It was nowhere near as severe as the Dow's most well-known, one-day drop of 508 points, or 22.6 percent, on Oct.