They effect every aspect of our lives. Many of them live on living organisms such as animals and plants. They are incredibly diverse and can exist and survive in a wide variety of environments. What are we talking about? Microbes.
What is a microbe? Well by definition, a microbe is a microorganism that can cause disease. There are few different types of microbes including: bacteria, algae, fungi, and viruses.
So what exactly does a microbe do? The majority of microbes are harmless, but some can causes diseases like the flu (a viral infection cause by the influenze virus) or malaria (which are spread through mosquitos and act as a paraside).