Doji
A doji is a candle whose open and close are almost at the same level. It reflects indecision between buyers and sellers.
You recognise a doji by its almost non-existent body, often just a line, with wicks of varying length. There are several variants: the standard doji, the dragonfly doji (long lower wick), the gravestone doji (long upper wick) and the long-legged doji.
On its own, a doji doesn't mean much. After a long rally, below resistance, it can signal fading momentum. In the middle of a range, it is just noise.
Wait for the next candle for confirmation. A doji followed by a strong bearish candle at the top of a trend says far more than a doji on its own.