Cash advances are just that, advances of cash that you can borrow against your paycheck. They can be useful when you find yourself short of cash in between paydays. Cash advances are financial tools that need to be used very responsibly.
The main reason that people use cash advances is to cover emergencies that may arise in between paychecks but simply can't be covered in the normal budget. You should make sure that you know exactly how much your cash advance lender will ask you to pay back at the end of your term. The rate and fees associated with your cash advance can vary depending on the cash advance lender that you choose to get your cash advance from. Be sure that you have enough money in your account on the day that your cash advance is due to be paid back. If you don't, you could be hit with large late fees from the cash advance lender and overdraft fees from your bank.