Window is a two day potential trend continuation pattern. Window is a gap between two or multiple day candlesticks on the price chart of a security.
A window pattern happens where there is a gap between the high price of Day1 and low price of Day2.
A window with necessary confirmation during an uptrend of a security indicates that prices might move higher.Window usually acts as a support area.
For Downtrend, there will be a gap between the closing price of Day1 and the high price of Day 2. Window might indicate that prices will move lower and the window acts as a resistance area.
Psychology of Window pattern is that the gap/window on the chart is an area where no trading ( i.e buying / selling of the security ) took place. So it is considered as a continuation pattern pointing to the existing trend.
As like any other, piercing patterns require confirmation candlesticks in the following days. On a price chart of the security, if the window appears after an uptrend and prices subsequently close below the window and then continue downward then the pattern is voided and vice-versa if it happens during downtrend. 
