I am so lost and confused by this whole orfdeal!!

I just don't understand any of this....
Can i ask a few questions?
1. Who is paying this tax??
2 IF I have insurance through work , I am happy with, do I still pay this tax???
3> If I do have to pay this tax, how will it be done?? Through my paycheck (like Fica, medicare??)?? a bill from the government?? at the end of the year, by the IRS??
4. Why do I have to pay this tax, when people who already on Medicaid don't have to, because of no/limited income??
This should get you started...
Is there a link perhaps ??