Because bacteria and viruses cause many of the diseases we're familiar with, people often confuse these two microbes. But viruses are as different from bacteria as goldfish are from giraffes. For one thing, they differ greatly in size. The biggest viruses are only as large as the tiniest bacteria. Another difference is their structure.
Bacteria are complex compared to viruses.
In addition, it may have extra loose bits of DNA called plasmids floating in the cytoplasm. Some have threadlike structures called flagella that they use to move. A virus may or may not have an outermost spiky layer called the envelope. And that's it. Viruses are moochers.