Cash advances are given by bank against your credit card as a short-term loan. If a company other than bank provides cash advance, they take factors like future income and IRS tax refund into consideration.
Cash advances are acquired easily, but they have a couple of downsides. The amount available to loan is quite low, which makes it impossible for bigger purchases. The rate of interest and additional charges are also very high and there can be no deduction of taxes on these amounts. Cash advance serves best as last resort if one has an urgent need of money.