Some pure copper can be found in rocks. However, most copper is combined with other chemicals in rocks.
To get the copper from these rocks the rock is heated strongly in a furnace so that the copper melts. It then flows out of the furnace and cools into a solid. The pure copper is rolled out into sheets or drawn into wires.
Copper is important in circuits for several reasons. It does not rust like iron. It is also a very good conductor of electricity. It is soft and bends easily, so that twisted strands of copper wire can be used to make the flex or cable that connect electrical equipment to wall sockets.