What is volatility? In simple words, you can say that volatility is a measure of how large the price moves are.
The higher the volatility, the "riskier" the trading.
When the market shift from low to high volatility is often where the best trading opportunities appear...
For example, when price spikes into a level late in trends you often see a trend reversal.
And when price spike out of a level after low volatility period is often combined with a breakout type of technical pattern.