Smart Money Concepts (SMC) and ICT terminology can feel like a secret language. Stripped of the jargon, most of it describes the same underlying thing: zones where an imbalance between buyers and sellers left orders unfilled, which price tends to revisit.
Fair Value Gap (FVG)
When price moves so aggressively that a three-candle sequence leaves a gap, the first candle's high never overlaps the third candle's low, almost no trading happened in that slice of prices. Markets tend to return and 'fill' that inefficiency before continuing.
Order block
The last opposite-colour candle before a violent move often marks where a large player absorbed the other side and loaded a position. When price returns to that candle's range, the same participant tends to defend it.
Supply & demand zone
A broader version of the same idea: a tight consolidation 'base' followed by an explosive departure marks a zone of resting orders. Rally-base-rally forms demand; drop-base-drop forms supply. LazyChart draws these as shaded rectangles on the chart.
The honest caveat
None of these guarantee a reversal, they're areas of higher probability, not certainty. That's why LazyChart's SMC strategies require confirmation (a reaction candle, trend agreement, an unbroken zone) before signalling, and why every output stays informational, never advice.