What are germs, viruses, and bacteria?

Germs:

1. Germs are microscopic bacteria, viruses, fungi, and protozoa that cause diseases.
2. They can only be viewed under a microscope.
3. They can be found in the air, the soil, and the water.

Viruses:

1. A virus is a small infectious agent that replicates only when it enters a live host.
2. Viruses infect all living things, including bacteria and archaea, from mammals and plants to microbes.

Bacteria:

1. Bacteria are common, largely free-living organisms that are often made up of only one biological cell.
2. They make up a broad group of prokaryotic organisms.
3. Bacteria, typically a few micrometers in length, were among the first life forms to appear on Earth and can be found in nearly all of its habitats.