What Does Refinancing a Car Do?

refinancing

I got my car over a year and a half ago… it was financed @ 19%!!!!
Is it terrible to refinance?
I have a few credit cards; not behind in payments (or past due) but nearly maxed out! I have also been @ my job for two years now…
Would it help to refinance?
If so, how do I go about doing this?
also I don’t know if this matter but
- I don’ t use the credit cards now & I know you don’t keep credit if you get rid of them!!
–Recently I have a few offers to refinance my car – in the mail.