Electricity- conductors and insulators. help..?

We use electrical conductors for the flow of electricity. Power lines, speakers, outlets, and anything with wires would be a example. A wire itself would be a good example. We use electrical insulators anywhere we do not want current to flow at. A great example would be the insulation on wires that keep negative from touching the positive which would cause a short to accrue. Power lines would be another example of that considering each wire is separated by insulation. I do believe some of the nicer O' scope allows you to view the magnetic field produced.