The harami is a two day candle pattern. The first day of the pattern consists of a long bodied candle either black or white. On the second day a short opposite candle is formed. This generates a "wait and see" signal since it appears that the market is focused on the first large day, and on the second is waiting for more information. This is also seen since there should be lower trading volume on the second day.
! This pattern is often mistaken for an engulfing pattern but it is important to note the order of the candles.