Four numbers, one shape

A candlestick packs four prices into a single shape: the open, high, low, and close for a chosen time period, whether that's one minute or one week. The thick part, the body, spans between the open and close. The thin lines above and below, the wicks, mark the high and low reached during that period.

When the close is higher than the open, the candle is typically green or white, a bullish candle. When the close is lower than the open, it's typically red or black, a bearish candle. Reading a chart is really reading a sequence of these small stories about who won the fight between buyers and sellers.