Movement along demand curve occurs when price changes, causing quantity demanded to change while demand itself remains constant. Shift in demand curve occurs when non-price determinants change, causing the entire curve to move. Key difference: Movement = temporary response to price change; Shift = fundamental change in demand. Movement examples: Price of petrol rises, demand quantity falls (movement down curve). Shift examples: Income increases, demand for cars increases (entire curve shifts right). Graphically: Movement shows as points along the same curve; Shift shows as entire curve moving. Causation: Only price causes movement; everything else causes shift. Reversibility: Movement is reversed when price reverts; Shift may be permanent if determinant change is permanent. MCQ trap: Questions mixing both concepts—identify cause first (price vs. non-price). Indian example: Demonetization shifted demand curves suddenly; subsequent price adjustments caused movements. ICAI tests: Distinguishing concepts, identifying causes. Exam tip: If question involves price change, it's movement; if determinant or preference change, it's shift.