What actually is current and resistance?

[tbenner]

I'm reviewing electronics and am on simple DC circuits at the moment. I know current is the flow of electrons, but what happens to electrons as they move through a wire? Electrons are attracted to the positive terminal of the battery or power supply, but does the electron re-combine with other atoms in the valence orbit as it moves along and then gets knocked out again, or does the electron stay a 'free' electron?
And how does a resistor work? Does it reduce the potential difference field that the electrons feel, so fewer electrons flow? What does a resistor actually do at the atomic level, to reduce current flow?

Thanks

[Tim]

 

[(*steve*)]

Electrons move very slowly.

Imagine the pipe full of billiard balls. As you push one in one end, another pops out of the other -- that is current. It moves very quickly, but the electrons (the billiard balls) move very slowly.