In American English, 'money' has many alternate slang words. Cash is used when talking about actual paper money. Usually 'money' is used in more general terms, "I don't have any money till the end of the month, when I get paid." It would be common in America to be asked, "Are you paying with cash or credit?" In this instance, cash means actual currency and is not interchangeable with 'money'. Probably the second most used American slang for money is 'bucks'. The word is most likely derived from 'greenbacks'. One buck means one dollar, so common usage would be, "How much did it cost?" "Two bucks".
Other common slang words for 'money' are dough, scratch, bills, moolah, C-notes ($100-bills) or Benjamins (Benjamin Franklin's face is on the $100 bill),