Convection is the movement of warm particles within fluids. Convection is often found in the air as heated air rises and cool air falls. This is because hot molecules spread apart, making them less dense and causing them to rise. Convection is also found in the ocean as currents of different temperatures travel and interact.
Convection, convection is the heat movement the heat transfer due to the movement of particles. Remember, when there's energy, energy is kinetic energy and kinetic energy causes particles to start to move faster and as they move faster they're going to start to spread out and they're going to expand and, and the movement of those heated particles is going to carry that energy with it so some examples of this are currents for example the Gulf of Mexico we've got a body of water and that water is getting heated up that water is expanding. As the water expands it's going to move North and that heated water travels all the way to Europe and helps heat Europe and keep these very northern latitudes fairly comfortable due to this expansion of water due to convection.
We also see this process occur with air currents, so around the equator we have a lot of hard air, that hard air expands and it rises and it moves north and south and carries that warm air north and south where it eventually cools off and settles down so convection simply is just the movement of energy due to the transfer of heated molecules.