The characteristic odor of garlic is due to the presence of sulfur-containing compounds. Garlic is a member of the Allium family, which also includes onions, leeks, and shallots. When garlic is crushed or cut, it releases an enzyme called alliinase, which converts a sulfur-containing compound called alliin into allicin. Allicin is responsible for the distinct smell of garlic.

Sulfur-containing compounds in garlic are also responsible for its health benefits. Allicin and other sulfur compounds have antimicrobial and antioxidant properties, and they may help reduce the risk of certain diseases such as heart disease and cancer. However, it`s important to note that the beneficial compounds in garlic are released when the cloves are crushed or chopped, so consuming raw garlic or using it in cooking is more effective than taking garlic supplements.

In conclusion, the characteristic odor of garlic is due to sulfur-containing compounds, specifically allicin. These compounds also contribute to the health benefits associated with garlic consumption.