Definition: Volatility refers to how easily a stock tends to rise and fall. A volatile stock would be one that sees very large swings in its stock price.
TeenAnalyst Advice: Some industries are traditionally more volatile than others. For example, technology stocks are considered to be extremely volatile. Price swings of 5-10% in a single day aren't uncommon.
It's always a good idea to diversify your portfolio. That way, if you have one or two volatile stocks in your portfolio, you won't have to worry about your overall portfolio having big swings.