what is resistance and support and how to use it in trading ?

Support occurs at the point where a downtrend is expected to pause due to a concentration of demand. Resistance occurs at the point where an uptrend is expected to pause due to a concentration of supply. Support and resistance areas can be identified on charts using trendlines and moving averages

Using Support and Resistance After a Breakout
Old Resistance Becomes New Support – If the price breaks above resistance, that resistance level may now act as support.
Old Support Becomes New Resistance – If the price breaks below support, that support level may now act as resistance

TOP-10 Support and Resistance Indicators
Fibonacci Levels.
Support and Resistance Zones Indicator.
Linear Regression.
Margin Zones Indicator.
Trend Lines.
Fair Value Gaps.
Stacked Imbalance Indicator.
Psychological Levels.