Since I was forever confused about these topics - specially right before I wanted to cook Chicken or Fish Tikka, I decided to research it once and for all and share it for everyone out there like myself.
Roasting - It is dry heat enveloping the items. It is used for cakes/pies, casseroles, or breads. Most commonly used with vegetables, beef roasts, and poultry.
Broiling - Very high, nearly-direct heat applied at close proximity, usually for very short amounts of time. Best for searing the outside of an item, while minimally cooking the interior, or adding color, or melting cheese on an otherwise cooked dish. Some items like fish/seafood are light enough density that the inside will cook within the short amount of time it's under the broiler while the outside browns/sears.
