Balance Transfer credit cards are credit cards that allow you to transfer the balance on an existing card to a new one, allowing you to take advantage of the introductory 0% APR period. This is useful because of the following situation :
Say you have credit card debt on the order of $20,000, and the card you have gathered the debt on is no longer in its introductory APR period. You could use a balance transfer card and transfer all $20,000 to the new card, often with up to a year of 0% APR. This means that instead of paying over $4,000 in fees every month for most cards, sometimes even more, you have a year to pay off the debt with no fees at all.
Applying for a credit card to balance transfer is a great way to save on your existing credit card debt, they also often offer extended lowered APR periods, so they can also provide a way to help with a large purchase. Many credit cards have 0% APR balance transfer rates for 6-18 months. The secret to saving more with these credit card offers is to be aware of balance transfer fees and different interest rates for purchases.
Some credit cards have a 3% balance transfer fee with a maximum fee of $75 or $90. These fees are okay if you can take advantage of a 0% APR for more than 12 months. The fees were created so people couldn't credit card balance transfer surf (continuously transferring balances to avoid interest).