So one very common example of a virus, one very common type of a virus is a bacteriophage. And a bacteriophage is a virus that only targets and infects bacterial cells. So basically, the structure of our bacteriophage looks something like this. We have our nucleic acids, either DNA or RNA, found inside the protein capsule. This is the protein capsule also known as the head of our bacteria phage. We also have a protein midsection as well as the protein tail.