Why does smoke disperse but clouds seem to stick together?

The particles that make up smoke and clouds have important differences, which explains how they appear.

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How do clouds in the sky maintain a relative shape over time instead of just wispily blending with the air around it like smoke in wind? - Quora

Why does smoke disperse but clouds seem to stick together?

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Why do clouds usually appear as a line in sky? - Quora

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