GMOs (Genetically Modified Organisms) are living organisms that have had their DNA changed in some way. When genetically modifying, scientists are able to pick one desired trait from an organism and insert it into another. This allows only the desired traits to be transferred instead of all of them.
This is an alternative to conventional breeding. Conventional breeding involves mixing all of the genes from two different sources. This process has been being used for centuries.
The Science of GMOs 