Protists are a diverse group of eukaryotic organisms that are not animals, plants, or fungi. They are single-celled organisms, meaning they are made up of only one cell. Some examples of protists include amoeba, paramecium, and algae.

While some protists are microscopic, others can be quite large, like the giant kelp. While they don't have the same complex structures as multicellular animals, they are capable of performing all the functions necessary for life, such as eating, breathing, and reproducing.