The phrase "previous candle" refers to the candlestick on a price chart that came just before the current one. It represents the price movement that occurred in the timeframe immediately before. Full definition
So, I see both candles closes from previous candle, however the second picture doesn't confirm as for as the wick, it's much longer, in that case I don't take the trade? (fxdayjob.com)
If you see previous candles are bullish, you can anticipate the next one near the underneath of the body low will trigger a short / sell signal when the doji lows break. (daytrading.com)
To be a bearish confirming candle, it needs to close below the previous candle. (fxdayjob.com)