bipolar leads ecg

can anybody help me with ECG? THANKS IN ADVANCE?
can you please tell me what is meant by the leads of the ECG.
when they say that it is the record obtained from electrodes.
and then they say bipolar leads:
which means that there is two active leads, and one Reference ( that is only there for finishing the electrical circle.
how can we obtain one diagram from two electrical source?
arent we suppose to get two diagrams( one for each lead?)
and when we have nine position where we can put the electrodes.does this mean that we have 18 electrodes(8 Reference) and do they usually get 9 diagrams per ECG.one from every active electrode.
thanks alot churry : )
two active leads is not an ECG, that is simply telemetry. It takes 12 leads to get an ECG. The following website is a good place to start educating yourself about ECG.
http://www.ecglibrary.com/ecgfaq.html