copper is the best conductor of electricity because the electrons in copper can easily transferred from one atom to another and the electric current is based on the flow of the electrons through conductor.
Electrical conductivity in metals is related to the ability for electrons to flow through them. Not all metals offer the same opposition to electron flow. Metals that have high conductivity have low resistance.Thus, copper is a good conductor of electricity because it has many free electrons
Metals are good conductors of electrical current as electrons can flow freely within them. Copper is one of such. The sea-of-electrons within a metal is a good example of hoe each electron can float freely.
Copper is the conductor of choice where the rate of conductivity isn't that critical. Gold is the fastest and most reliable conductor. However, if the price of gold is prohibitive, silver is the next best choice. Aluminum was in vogue for awhile, but friction in this metal sometimes caused fires.