Both words are similar in meaning. Frequently, they are used in the application of genetic engineering to refer to organisms that have suffered a genetic modification. This involves a technique whereby individual genes can be copied and/or transferred from one organism to another, altering its genetic makeup and thus incorporating or deleting specific characteristics.

Sometimes, manipulation is also used to refer to the natural process of gene selection and mutation that occurs in nature in the breeding of animals and plants, as part of the process of evolution, which allows the development of new species that have specific use for humans.

Organisms that have been genetically manipulated have also been described as having been “genetically improved” (GI).