An Algae is a term mentioning a group of photosynthetic eukaryotic organisms. It has chlorophyll and nucleus but no root, stem, leaves and many features like normal land plants. Algae is both unicellular (e.g. Euglenophyta) and multicellular (e.g. seaweeds). Algae do photosynthesis and help in oxygen production
Algae can live in various habitats like moist rocks, soils, water bodies (both freshwater and marine) and in some animals (e.g. Sloth). Unicellular Algae belong to the Protista Kingdom and Multicellular algae belong to the Plantae Kingdom, but formerly all algae are categorized under kingdom Plantae for their photosynthetic nature.
Also Read: Difference Between Algae and Fungi