"In accounting, a current asset is an asset on the balance sheet which is expected to be sold or otherwise used up in the near future, usually within one year, or one business cycle - whichever is longer. Typical current assets include cash, cash equivalents, accounts receivable, inventory, the portion of prepaid accounts which will be used within a year, and short-term investments." http://en.wikipedia.org/wiki/Current_asset
"Media credits" is another term for Prepaid Media. Like buying your car insurance one year in advance you have "Car Insurance Credits" listed under current assets.