Genome editing, or genome engineering, or gene editing, may be a sort of gene-splicing during which DNA is inserted, deleted, modified or replaced within the genome of a living organism. Unlike early gene-splicing techniques that randomly inserts genetic material into a number genome, genome editing targets the insertions to site specific locations. gene-splicing as method of introducing new genetic elements into organisms has been around since the 1970s. One drawback of this technology has been the random nature with which the DNA is inserted into the hosts genome. this will impair or alter other genes within the organism. Methods were sought which targeted the inserted genes to specific sites within an organism genome. also as reducing off-target effects it also enabled the editing of specific sequences within a genome. this might be used for research purposes, by targeting mutations to specific genes, and in gene therapy. By inserting a functional gene into an organism and targeting it to exchange the defective one it might be possible to cure certain genetic diseases.