Genetically modified (GM) organisms occur when genes from one living thing, such as a plant, animal or bacteria, are transferred to another.
This is due to the gene causing a desirable trait, such as resistance to a pathogen that normally wipes out crops.
GM allows genes to be transferred between closely related organisms, such as from a wheat to a rice plant, as well as from a fish to a strawberry.
Benefits include increased productivity for agriculture by raising crop yields while reducing the need for pesticides.
Yet critics argue the long-term health and environmental consequences of GM are unknown.
Some worry GM allows antibiotic-resistant genes to be transferred between species, as well as it potentially increasing the risk of allergies if people are intolerant to a food whose genes are then transferred to another.
In Europe, GM produce must be labelled as containing genetically modified ingredients, with such labeling not being required in the US. EU regulations also restrict GM products.
Developing countries could benefit the most from GM due to such regions often relying heavily on agriculture, with genetic modification boosting food production, in theory.