What exactly is a portion or a serving of vegetables or fruits ?

What exactly is a portion or a serving of veg or fruits ?

A portion of fresh fruits or veggies is 80 grams. The World
Health Organisationrecommends at least 400 grams of fruits and vegetables
daily to prevent obesity,heart disease, cancer and type 2 diabetes.

 So breaking this 400 into five servings means each serving should be around 80 grams.

Info source: http://articles.timesofindia.indiatimes.com/2012-01-14/diet/30477152_1_fruit-juice-portions-european-heart-journal