Well, conduction is the passing of heat by touch. Convection is the passing along of heat by movement (e.g. hot air rising from a radiator to heat the rest of the room), and radiation is the heating of something through electromagnetic rays without any contact. For example, the earth absorbs the heat radiated from the son (radiation). The air that touches the earth gets warmed up (conduction), and rises, and as it rises, it passes its heat along to more air around it (convection).