What it means
Green (bullish) candles closed above their open; red (bearish) ones closed below. Candlesticks trace back to Japanese rice traders in the 1700s.
In practice
One candle tells the story of its period. The body shows who won between the open and the close, the wicks show how far price travelled and was pushed back, and the size shows how much energy was behind it.
Traders read candles in context rather than one at a time: a large body closing through a level, a long wick rejecting one, or a run of small candles showing a pause. The same shape means more at an important level than in the middle of nowhere.
What to watch for
A candle is only final when it closes. A strong green candle can turn into a long upper wick in its last minute, so decisions based on a close should wait for the close.