Answer:
force convection is where the surface is forcefully heated up and the to is cooled down where when Nature happens, The photons come from the sun and bounce of the mlecules which creates heat and warms the air around it and that warm air heats up and goes up because it is less dense then the colder air. There it cools down and sinks because it is more dense than the air around it and it hits the ground only to be reheated and continues the cycle