Apparently, there is a little bit of confusion out there about the difference between portion and serving size. This graphic from the International Food Information Council breaks it down.
Food Insight is the information hub created and curated by nutrition and food safety experts at the International Food Information Council (IFIC). IFIC is a nonprofit 501(c)(3) education and consumer research organization with a mission to effectively communicate science-based information about food safety, nutrition, and sustainable food systems.