Candlestick
A candlestick is one period on a candlestick chart: a body between the open and the close, and wicks to the high and the low. A green or hollow candle closed above its open; a red or filled one closed below.
The body shows how far price moved from open to close; the wicks show how far it went and came back. A long lower wick means price fell and was bought back; a long upper wick means it rose and was sold off. A candle shows the four prices but not their order: whether the high or the low came first is visible only on a lower timeframe. Traders also call it simply a candle.
Learn more: what is a candle? How to read a candlestick and what a long wick means.