Conversation so far:
What are the most common spices used in cooking?
The infographic above shows that, surprisingly, cumin is the most popular spice in the world, and coriander (or cilantro) is the most commonly used herb. In Europe and Africa, garlic is the most common among all dishes considered, and—no surprises here—oregano is common in the Mediterranean regions.

Question: How are they different from herbs?
Self-contained rewrite: How are spices different from herbs?