Support, as the name implies, indicates a price level or area on the trading chart​ under the current market price where buying interest is sufficiently strong enough to overcome selling pressure. As a result, a decline in price is halted and prices are turned back up again.

Resistance is the opposite of support. It represents a price level or area above the current market price where selling pressure may overcome buying pressure, causing the price to turn back down against an uptrend. It should be emphasised that an existing prior high does not imply that subsequent rallies will definitely fail at or below that high with pin-point accuracy, but rather that resistance could be anticipated in the general area.