They are simple, unicellular eukaryotic organisms.
They are neither plants nor animals or fungi.
Mode of nutrition- autotrophs (prepare their own food), heterotrophs (obtain nutrition from other organisms), and some are decomposers (obtain nutrition from decaying matter).
Some of them can be infectious. These organisms live in their host and obtain their nutrients at the host's expense.
Examples of parasitic protists:Plasmodium (causes malaria), Trypanosoma (causes sleeping sickness), and Toxoplasma (causes toxoplasmosis).