What are the differences between chives and scallions in terms of flavor, appearance, and culinary uses?

Chives have a mild onion flavor and a grass-like appearance with thin, hollow leaves, while scallions have a stronger onion flavor and a thicker, solid stalk with a white base and green tops. Culinary uses differ as chives are often used as a garnish or in dishes where a subtle onion flavor is desired, while scallions are used in a variety of dishes for their stronger onion taste.