cas9 is what

is known as a CRISPR-Cas system. It is a type of technology that uses the naturally occurring system of bacterial defense to edit DNA sequences in living cells. CRISPR-Cas9 works by targeting specific DNA sequences and cutting them, allowing scientists to modify or replace those sequences with new ones. This technology has revolutionized genetic engineering and has been used in research on many different organisms, including plants, animals, and humans.