A greenhouse is a structure in which plants that need controlled climatic conditions are grown. It is commonly made up of glass. This size of these structures ranges from small sheds to industrial-sized buildings. A tiny greenhouse is known as a cold frame. The interior of a greenhouse is exposed to sunlight in cold weather to make it warmer than the external ambient temperature, protecting the crops. The chief crops grown in greenhouses are pepper, tomato, cucumber, lettuce, herbs, and strawberry.
The greenhouses were traditionally constructed on wooden frames with glass cladding material. With the advancement of plastic technology, glass is replaced with plastic material. Polyhouses are more appropriate for tropical and subtropical regions like India.