Support and Resistance is a very important concept in trading.
Support is the area where price finds great buying pressure and bounces up.
Resistance is the area where price finds great selling pressure and bounces down.
Highs and lows made on the daily and the weekly charts are good areas of support and resistance.
Using support and resistance in your trading can increase your trading accuracy.
Once support is broken it becomes resistance.
In the same manner once resistance is broken it becomes support.