How does solar electric propulsion (ion propulsion) work?

How are ions accelerated?

Ions act magnetically. Like magnets, they are attracted to things with the opposite charge and repelled from things with the same charge. The solar ion propulsion system on DS1 takes advantage of this to accelerate ions.

A positive ion will move towards (be accelerated towards) a negatively charged object, and away from a positively charged one. The force of the attraction depends on the difference between the charge of the attracting object and the repelling object. The more difference (called electrostatic potential) there is, the faster the ion moves. The greater the charge on the object, the faster the ion will try to move towards that object.

What is a ion?
How does DS1's engine work?
How could something as small as an atom move a space craft?
What is the difference between an ion engine and a conventional one?
What are other ion using technologies?

What does electrically charged mean?
What causes ions to leave DS1?
How are atoms charged?
Are ion engines radioactive?
Are ion engines nuclear?