Greenhouses are designed to take advantage of solar radiation to create a proper environment and temperature for plant cultivation.  Solar radiation heats all greenhouse contents, and the glazing traps the heat generated within the structure.  Even heating of the greenhouse contents mitigates the loss of heat by convection (warm air tends to rise and escape a structure), which is another important functional aspect of a greenhouse.  Greenhouse building components consist of a foundation, framing, glazing, ventilation, utilities and thermal storage systems.  Temporary and portable greenhouses may not require all these components.