Roasting is a way of baking meats, and toast usually a way of browning already-baked bread.

An easy way to remember is by considering the technology or machine that we use. Roast = uses a real oven, and usually is meat or root vegetables like potatoes. Toast = uses the machine that we call "a toaster" (usually), and bread is the food that is most often toasted. These words can also be nouns, but that is another question.

No this is quite different: you roast a chicken in an oven, and you put slices of bread in a toaster, which makes them hot and crisp... Yum🙂!

They both involve high heat. But TOAST implies a short time. Also, TOASTING isn't actually cooking, in my opinion. It' just turning something brown and crusty. ROAST also involves high heat, but it can continue for a long time--to cook a piece of meat or potatoes, for example.

Hello Geraldine, Just a little addition to Ann MC's comment... Roasting, in the cooking context, particularly refers to prolonged heat exposure of food, especially meat, whether on a fire or in an oven, whilst toast refers to cooking or browning (food, especially bread or cheese) by exposure to a grill, fire, or other source of radiant heat.