Nutrition in plants can be classified into two- Autotrophic and heterotrophic nutrition.
Autotrophic plants prepare their own food by photosynthesis.
Heterotrophic plants  depend on other organisms for  their nutrition and they cannot synthesize their own food.It can be further classified into three-
 *Parasitic nutrition in which the plant is entirely dependent on their host plants/ animals for nutrition like cuscuta and mistletoe
* saprophytic nutrition in which the plant obtains it's nutrition from dead and decaying matter like mushrooms
* Symbiotic nutrition like that of lichens, where they form a symbiotic relationship with algae by living in the same colony.Here, algae provides food for lichens whereas, lichens provide water, nutrients and shelter for algae.