Support
A price area where falling prices have stopped and turned back up before.
Support is a price area where a falling market has stopped and bounced more than once. It forms because buyers have stepped in around that price before, so many traders watch it again.
Support is better thought of as a zone than a single exact line. Price can dip a little below it and still hold. The more times a zone holds, the more people notice it, but no level is guaranteed to hold the next time.
When support breaks clearly, it often changes job and starts acting as resistance on the way back up. Traders use support to decide where a plan is wrong, not to predict a bounce.
Example: a market falls to about $100 three times over a month and each time turns back up. The $99 to $101 area is a support zone.
New to all of this? Start learning trading from zero.
Educational definition. Not financial advice; no real-money execution.