A trend is a direction, not a single move
One green candle is not a trend. A trend is the overall drift of price across many candles. We read it through the peaks and valleys price leaves behind, like footprints showing which way someone walked.
Uptrend — higher highs AND higher lows, stair-stepping up
Downtrend — lower highs AND lower lows, sliding down
Sideways — highs and lows stuck in a flat range