Recombinant DNA technology involves linking DNA fragments to self-replicating vectors to create recombinant DNA molecules, which are then replicated in a host cell. DNA is cut with restriction enzymes, isolated, and ligated into a cloning vector before being transformed into a host cell. Recombinant DNA technology is widely used in biotechnology, medicine, and research for applications such as producing insulin, developing drought-resistant crops, and creating recombinant vaccines.