Genetically Modified Organisms ( GMOs ) are organisms such as plants, animals and micro-organisms (bacteria, viruses, etc.), the genetic characteristics of which have been modified artificially in a way that does not occur naturally through fertilisation and/or natural recombination in order to give them a new property (a plant’s resistance to a disease or insect, increased crop productivity, a plant’s tolerance of a herbicide, etc.). GMOs may be plants, animals or micro-organisms, such as bacteria, parasites and fungi.
How GMO’s are created ?
Reference : ec.europa.eu
You may also check information about GMO’s from WHO website at “Frequently asked questions on genetically modified foods”