Support
Support is a price level where buying has repeatedly emerged strongly enough to halt or reverse a decline.
Price bouncing off support
Support is a floor — a level where falling price has historically attracted enough demand to stop the drop. Traders watch it because price approaching support is a spot where a bounce becomes more likely, and a clean break below it often signals further downside.
Support is not a single exact price but a zone, and it gets stronger the more times it holds. A moving average can also act as dynamic support that rises and falls with the trend — see the moving averages guide.