A support level is a price floor where buyers keep stepping in. A resistance level is a price ceiling where sellers keep stepping in.
Support and resistance are the most referenced concepts in all of trading. Support is a price level where buyers have stepped in before — the more times it's been tested and held, the stronger it is. Resistance is the mirror: a price level where sellers have shown up. People often draw these as exact lines, but in reality they're zones — bands of a few ticks or points where orders cluster, because trading is never exact. When we say 'price hit support,' we mean 'price entered the zone where buyers have been sitting.'
Price drops to 100, bounces. Drops again weeks later — stops at the same 100 level and bounces again. That level is now 'support' because buyers have defended it more than once.
Two tests of the same level → support. The rule of thumb: tested once is nothing special — it's just a price. Tested twice is interesting. Tested three times is a real level where serious orders are sitting. Each successful defense makes the level stronger because more traders are watching it.
Why people mix it up: Both describe 'a price level where buying or selling happened.' Beginners mix them up once they encounter ICT terminology.
How to tell them apart: Support/resistance is the universal, loose definition: any level price bounced off more than once. Order blocks (ICT) are a stricter, more specific definition involving the last opposing candle before a displacement move. We're teaching the universal version here — the ICT version lives in its own module and builds ON TOP of this one.