现金 means 'cash' — physical money like coins and bills, as opposed to digital payments or bank transfers. Unlike 资金 (zī jīn, funds/capital for business or projects) or 金钱 (jīn qián, money as an abstract concept), 现金 is concrete and everyday. 钞票 (chāo piào) is a synonym for paper money but is less common in daily use.