Conduction

Convection is the process in which the molecules of substance(liquid or gaseous) reach the heat source and gain or loose the heat energy and move away. Which can be seen when we heat the water in a pot, it starts boiling this boiling is molecules which after heating at the bottom of the pot become lighter in weight hence move up and the cooler molecules at the top come down because of there higher weight. The process continues till you continue heating. Conduction is normally can be seen solids. heat from the source is trasmitted to the adjusent molecule thus heating the whole object. The molecules closer to the heat source are comparatively hot than the farther one. The example can be given as heat a steel rod on one end slowly the other end also gets heated. The heat travelled through the solid bar by transmitting the heat by heating the adjuscent molecule. For detailed understanding you can refer any physice book kwpt as text book for middle school level.