Read the Defining Genetically Engineered Organisms white paper.
GMO stands for ‘Genetically Modified Organism.’ However, this is a somewhat flawed designation, since virtually all farmed and domesticated organisms (plants, animals and our pets) have been genetically modified for thousands of years. In our current usage, genetically engineered (GE) refers more precisely to an organism whose genetic material has been altered by means of genetic engineering.
Therefore, a GE organism is defined based on the way in which it was originally produced (genetic engineering), and not on the characteristics (or ‘traits’) it shows. The traits of a genetically engineered organism can vary dramatically – from herbicide tolerance to vitamin fortification – much as genetic material can vary dramatically among different organisms.