Three White Soldiers is a candlestick pattern which very difficult to see but very accurate signals. This is the contrast pattern of the Three Black Crows.
Pin Bar candlestick pattern is about special candlestick with a short body completely lay on a side and long tail. Helpful in strategies and indicators.
Gap occurs when the closing price is different from the opening price of the next candle in candlestick chart. In technical analysis, it's a no trading area
Three black crows are visual models that are useful by difficulty at a comfortable level. This is a reversal warning candle pattern, not too hard to learn.