Question

it is more comfortable to sit on a bed then on fence give reason​

Answer 1

If this is a physics question, the answer is-

A fence requires you to sit on a very minute area, thereby decreasing area. Since Pressure= Force/Area, then a decrease in area will lead to increased pressure.

A bed on the other hand, allows you to occupy a larger area, increasing area. Similarly, P=F/A, therefore pressure on your body will be decreased. So, you can sit more comfortably.

Note: Here, the force is actually that applied by the object on your body

Answer 2

A bed is soft a fence is not. You can modify your warmth in a bed (by adding or taking away blankets) you can't on a fence, you will be whatever the weather is. Some fences have pointy things on the tip (chain-link) so that makes them less comfortable.