In spherical..there is concave reflector..n in box it's plane 1...as compare to box type cooker.. spherical has quite more temperature..n it can also cook food which needs strong heating..

Box Type Solar Cooker vs Spherical Type Solar Cooker

Design:
- Box type solar cookers are rectangular in shape and have a flat surface where the cooking vessel is placed.
- Spherical type solar cookers, on the other hand, are dome-shaped and have a spherical reflective surface that concentrates sunlight onto the cooking vessel.

Efficiency:
- Box type solar cookers are generally more efficient for cooking larger quantities of food due to their larger surface area for capturing sunlight.
- Spherical type solar cookers are more efficient in terms of focusing sunlight onto the cooking vessel, resulting in faster cooking times.

Portability:
- Box type solar cookers are usually bulkier and less portable compared to spherical type solar cookers.
- Spherical type solar cookers are more compact and easier to transport, making them ideal for outdoor activities or camping.

Cost:
- Box type solar cookers tend to be more affordable and easier to construct using simple materials like cardboard and aluminum foil.
- Spherical type solar cookers are more complex in design and may require more expensive materials, making them pricier to purchase or build.

Versatility:
- Box type solar cookers are versatile and can be used for various cooking methods such as baking, boiling, and steaming.
- Spherical type solar cookers are specifically designed for focused cooking and may not be as versatile for different cooking techniques.
In conclusion, the choice between a box type solar cooker and a spherical type solar cooker depends on factors such as cooking needs, portability, budget, and versatility. Both types have their advantages and limitations, so it's important to consider these factors when selecting the most suitable solar cooker for your needs.