How many cups are in a serving?

That depends on what the serving is made of.

If it's a serving of grains, it would be 1/2 cup of rice, pasta, or hot cereal (oatmeal, etc.), or 1 cup of ready-to-eat cereal (cheerios, lucky charms, etc.).

For vegetables, it's 1/2 cup of raw or cooked veggies (broccoli, cauliflower, etc.), or 1 cup of leafy raw vegetables (spinach, kale, etc.).

A serving of fruits would be 1 cup of fresh fruit or 100% fruit juice, or 1/2 cup of dried fruits (raisins, dates, banana chips, etc.).

Dairy actually has 3 sizes; 1 cup of milk or yogurt, 11/2 cups of ice cream, and 1/8to 1/4 cup of cheese.

Proteins have even more serving sizes. For lean meat, poultry, or fish, it's 1cup (when converted from ounces), for cooked beans, the serving is 1/4 cup. The serving for nuts or seeds is 1/16 cup, and then there's eggs and peanut butter, which can't be measured in cups (1 egg, 1 tablespoon of peanut butter).

Oils are measured in teaspoons because the serving size is so small.

There are 1/2 cups in a serving.