Swings

Swing High and Swing Low as discussed in Bounce Theory

A Swing Low is the low of the candle that has a higher low on either side. A Swing High is the high of the candle that has a lower high on either side.

In the case of Swing High, the high of the neighbour candles are lower than the high of the main candle itself.
In the case of Swing Low, the low of the neighbour candles are higher than the low of the main candle itself.