Zones & imbalances
A long, one-sided run of big candles that price tends to come back and fill.
A liquidity void is a stretch of price delivered in one direction only: a run of large candles with little or no overlap, where the market barely traded the other way. ICT describes it as a range that will be 'covered back over' at some point.
It is a bigger version of the fair value gap idea, spanning several candles. A vacuum block is a related term for a gap left by a sudden event, such as a news release or a session open; some traders use the two words interchangeably.
For education only, not financial advice.