What is the difference between demurrage and detention in product classification principles?

Demurrage and detention are charges when containers aren't moved quickly enough. Demurrage: Fees charged by the port/terminal when a container stays beyond the allotted free time (typically 3-5 days) before being picked up. Rates: $75-300 per day depending on port and container size. Detention: Fees charged by the shipping line when the container isn't returned empty within the free time after pickup (typically 7-10 days). Rates: $50-150 per day. To avoid both: 1) Pre-clear customs before arrival, 2) Arrange trucking in advance, 3) Unload and return container quickly, 4) Request extended free time in carrier contract (14-21 days), 5) Use a container yard for temporary storage. These fees can add $500-2,000+ if not managed properly.