Copper, is an element, on the Periodic Table of the Elements. It is number 29, and has the symbol Cu. Pure copper has an reddish-orange color, and it is the one of the few naturally occurring metals to be completely usable in metallic form, opposed to extraction from ore, this actually lead to early human use during the neolithic and paleolithic era from (c. 8000 BC), and the first metal to be smelted from it's ore (c. 4500 BC).
During the time of the Romans, it was mined on Cyprus, the original name of the metal, later corrupted to "cuprum", which later became the letter copper as it is today.
Copper has an extremely low electrical resistance and highly conductive as well. It also is highly thermally conductive. Thus copper is used for making products such as heatsinks and electrical cables. Alternatively silver can be used too due to its even higher conductivity. But since silver is more expensive, copper is used instead.