Interest (Finance Charge) is charged on every loans and credit card accounts that are not paid in full by the payment due date The Finance Charge formula is: Average Daily Balance x Annual Percentage...
Its' when a creditor/lender closes your account due to non-payment. This process takes place for tax purposes (so it's not a complete loss to the creditor/lender).
Generally, no, not for individuals. The costs to break a loan contract are not typically deductible for an individual, but MAY be deductible for a company or a trust holding the loan.