Credit Card & PCI compliance.

I have questions which regarding PCI compliance.

0.
Would someone able to shed some light on how the credit card logic work?

1.
Does it contact the credit card authorize gateway for a small authorize
amount and
void if success. Then captured the final CC amount at the order picking
and shipping manifest process?

2.
Does it keep or store the customer Credit Card information on the OFBIZ
server?
Credit card information such as:
PAN, expiration, CVV...

3.
If it stored credit card information on the server, does it encrypted
before written to
the database?

4.
If it store the CC information on the server but doesn't encrypted.
Does anyone has done this before?

Thank you.
Tom