I have heard about breath tests and blood tests and about an intoxilyzer test. What is the difference in these various tests and what is an Intoxilyzer?

Georgia uses the Intoxilyzer 5000 manufactured by CMI, Inc.  It purports to measure the amount of alcohol in your blood by testing your breath, which is a stretch, in my opinion.  The best way to determine the amount of alcohol in your blood is with a blood test, not a breath test.  By the way, would you prefer to have a breath test on a machine that the manufacturer does not warranty to be fit for the purpose for which it was intended?  That's the kind of "no warranty" that comes with the machine.  Always, ask for an independent test of your BLOOD, when given the opportunity.  That will give the accurate reading of alcohol in your blood, not your breath.