We can attack this in a few ways, but for the sake of time, I will focus on a simple definition. A master candle – a mother candle, father candle, central candle, whatever you wish to call it – is when a candle’s presence overshadows next 4 candles that follow it.
For example, you can have an initial candle, for example, one large body and 4 candles that come after where the price action takes place within the range if the initial candle. It does not matter if the initial candle is a full body or a body with 2 wicks, the notion is that the price action (the next 4, in this case) occurs within the range of the master candle).
You can regard this as a range pattern with the range being the high and low of the master candle.