This works by physically removing a gene from one organism and injecting it into another so that it is able to direct the trait set by that gene.

http://agbiosafety.unl.edu/basic_genetics.shtml 

Nanotechnology is science, engineering, and technology conducted at the nanoscale. 

A centimeter is one-hundredth of a meter, a millimeter is one-thousandth of a meter, and a micrometer is one-millionth of a meter, but all of these are still huge compared to the nanoscale. A nanometer (nm) is one-billionth of a meter, smaller than the wavelength of visible light.

Here are a few illustrative examples:

·         There are 25,400,000 nanometers in an inch

·         A sheet of newspaper is about 100,000 nanometers thick

·         On a comparative scale, if a marble were a nanometer, then one meter would be the size of the Earth

Nanoscience and nanotechnology are the study and application of extremely small things and can be used across all the other science fields, such as chemistry, biology, physics, materials science, and engineering.

As small as a nanometer is, it's still large compared to the atomic scale. An atom has a diameter of about 0.1 nm. An atom's nucleus is much smaller -- about 0.00001 nm. Atoms are the building blocks for all matter in our universe. You and everything around you are made of atoms. Nature has perfected the science of manufacturing matter molecularly. For instance, our bodies are assembled in a specific manner from millions of living cells. Cells are nature's nanomachines. At the atomic scale, elements are at their most basic level. On the nanoscale, we can potentially put these atoms together to make almost anything.

https://science.howstuffworks.com/nanotechnology.htm 

Where did it begin?

In 1959 before the term nanotechnology was coined, physicist Richard Feyman described a process in which scientists would be able to manipulate and control individual atoms and molecules. A decade later, professor Norio Taniguchi coined the term nanotechnology when exploring ultra-precision machining.

https://www.nano.gov/nanotech-101/what/definition