Glossary
Support and resistance S/R
In short
Support is a price area where falling prices have stopped before, resistance one where rising prices have stopped before. Traders expect a reaction when price returns to it.
Zones rather than lines
Price rarely turns at exactly the same tick. That is why many traders draw support and resistance as zones. Levels that appear on several timeframes at once get more attention.
Roles switch
When a resistance breaks, it often acts as support on the way back, and the other way round.
Levels wear out
Each test takes orders out of a level. A zone that has been tested many times can therefore get weaker, not stronger.