Seriously, go read Credit Scoring 101. You're asking questions that it covers.
We'd be delighted to help, it's just that getting that overall view first will help you make better sense of it.
* Credit is a wonderful servant, but a terrible master. * Who's the boss --you or your credit?
FICO's: EQ 781 - TU 793 - EX 779 (from PSECU) - Done credit hunting; having fun with credit gardening. - EQ 590 on 5/14/2007