Why is the virus called a parasite at the genetic level?

All viruses are parasitic. They enter the body and begin to act. Viruses have a very simple structure. They are made up of genetic information and a protein coat that surrounds DNA. It is because of this that viruses are called parasites at the genetic level. Most viruses are inactive. Only when they enter the body, they begin to show vital signs, multiply and destroy cellular structures. There are hundreds of thousands of viruses. Many of them have not yet been fully explored.