A swap zone is a Base that changes from Supply to, for example, demand. Or from Demand in Supply.
This is therefore called a swap zone and this is also often found in the charts.
Now another live example in the charts. The swap zone is also a very nice setup! Which I also really like to trade.
Above you see a nice example of a swap zone. Supply becomes Demand.
Take screenshots of 2 charts with a drawn swap zone.