What is a Vegetable? Serving sizes

For those of you who don't have experience with servings of fruits and vegetables it goes like this:

One serving vegetables equals:

1/2 cup cooked veggies

or

1 cup raw (such as lettuce)

One serving of fruit equals:

1 piece of fruit (apple, orange, banana, peach, etc.)

1/2 cup of sliced fruit

We want to get a general idea of what 5 to 9 servings equals. We don't want to go crazy about it. In Crete, they don't measure anything.