Long bodies refer to strong buying and selling pressure, if there is a candlestick in which the close is above the open with a long body, this indicates that buyers are stronger and they are taking control of the market during this period of time.

Conversely, if there is a bearish candlestick in which the open is above the close with a long body, this means that the selling pressure controls the market during this chosen time frame. 

Short and small bodies indicate a little buying or selling activity.