We were once afraid of bacteria, but then we found out that there are beneficial bacteria that battle harmful bacteria. In fact, we carry around plenty of bacteria that help our digestive systems work, which we call the human biome. And when we developed antibiotics, we no longer had to be so afraid of even harmful bacteria. But viruses are different, and we have no medicines to kill them, just vaccines to prevent their diseases. A lot of science later, we know there are tons of viruses that won't harm us, because they specialize in harming bacteria. Now we know that human bodies are teeming with viruses all the time, which is called the human virome. Like the biome, these colonies of viruses are crucial to our survival. Kurzgesagt explains how your virome works by performing several functions that make our immune system and other systems work the way they should.