From above we now know that Conductors are materials that have a low value of resistivity allowing them to easily pass an electrical current due to there being plenty of free electrons floating about within their basic atom structure. When a positive voltage potential is applied to the material these "free electrons" leave their parent atom and travel together through the material forming an electron drift.
Examples of good conductors are generally metals such as Copper, Aluminium, Silver or non metals such as Carbon because these materials have very few electrons in their outer "Valence Shell" or ring, resulting in them being easily knocked out of the atom's orbit. This allows them to flow freely through the material until they join up with other atoms, producing a "Domino Effect" through the material thereby creating an electrical current. Copper and Aluminium is the main conductor used in electrical cables as shown.
Generally speaking, most metals are good conductors of electricity, as they have very small resistance values, usually in the region of micro-ohms per metre with the resistivity of conductors increasing with temperature because metals are also generally good conductors of heat.