Horizontal price zones where price has historically reacted.
Support is a zone where price meets noticeable demand and usually turns back up. Resistance is the opposite: supply meets price here and halts advances. The most important property: after a break, support and resistance swap roles — old support becomes new resistance and vice versa (polarity flip). The more often a zone has been tested, the more significant it is. Suna AI Vision identifies relevant zones from tick history strictly walk-forward.
BTC H4: 65,000 USD was hammered as resistance five times, then broke. Two days later the same zone serves as new support for the pullback.