A candlestick chart is a combination of a line-chart and a barchart.

It records four prices : open, close, high and low.

1. The area between the open and the close is called the real body and price excursions above and below the real body are called shadows or leg.
2. If the close price is higher than the open real body is white and if the close is lower then the open real body is black.
3. Candlestick charts are visually superior to bar charts, and thus preferred by traders, because their coloured bodies help to identify support-resistance and trend lines and buy/sell signals.