What is convection, conduction and radiation and how do these work in space?

Convection is when hot gas or liquid rises over its colder part due to the density difference. Conduction is when molecules transfer heat molecule by molecule. Radiation is when heat or energy travels through light or another energy form.

Convection and Conduction don't happen in vacuums, such as space since there are no molecules and particles. Therefore, only radiation can happen in space.