balance transfer cards?

A question about : balance transfer cards?

What's the difference between balance transfer card to a standard credit card? Do balance transfer promotions apply to existing credit cards?

Best answers:

• Ok so once you go for a balance transfer card. Then you just use it as a normal credit card? And is the BT offer only the balance that's been transfered? Or does it include any purchases within that term?
• Also if you do a balance transfer then spend on that card, the spending will incur interest from day 1 (unless you also have 0% on purchases).
  So even if you clear the spending on each statement, it will still cost you some in interest