In Hindi, lichen is called "लाइकेन". It is a composite organism made up of a fungus and an alga or a cyanobacterium that live together in a symbiotic relationship. The fungus provides a protective environment and absorbs water and minerals, while the alga or cyanobacterium provides food through photosynthesis. Lichens can be found growing on rocks, trees, and soil, and they play an important role in the environment by contributing to soil formation and nutrient cycling.