4.6 describe how energy transfer may take place by conduction, convection and radiation

Convection is the transfer of heat by the upward movement of less dense (warmer) gas/fluid and the downward movement of denser, colder gas/liquid. NOTE: convection can not occur in solids or in vacuums

Conduction is the transfer of thermal energy through a solid (the solid doesn't actually move)

Radiation is the transfer of thermal energy in infrared waves. This is also the only method of heat/thermal energy transfer that can occur in a vacuum