Answer:
It is heat transfer as a result of density difference.
It is movement caused within fluids. Fluids are liquids or gas.
Example- Boiling water.
Particles near fire gain kinetic energy from the fire so they move fast and spread out. They rise up and cooler particles from the top fills in the bottom space. But then the cooler fluid also gains energy and rises up. This process keeps on going.
Convectional current is the motion of convection.
