Conduction

It is a mode of heat transfer in which heat is transferred from one area of a solid to the other.

It means that conduction takes place in solids. Conduction is the mode of transfer that takes place when you hold a hot metallic object. The heat from the metallic object is transferred to your hands so that in a short while, your palm becomes hot too.

In conduction, the colder area is in direct contact with the hotter area. Molecules present in the hotter area become energized by the heat. They vibrate and collide with nearby molecules, so that the nearby molecules also get heated and energized, and in turn transfer the heat to molecules present in the colder area.