In economics, cash is money in the physical form of currency, such as banknotes and coins. In bookkeeping and finance, cash is current assets comprising currency or currency equivalents that can be accessed immediately or near-immediately (as in the case of money market accounts). Cash is seen either as a reserve for payments, in case of a structural or incidental negative cash flow or as a way to avoid a downturn on financial markets.EtymologyThe English word "cash" originally meant "money box", and later came to have a secondary meaning "money". This secondary usage became the sole meaning in the 18th century. The word "cash" derives from the Middle French caisse ("money box"), which derives from the Old Italian cassa, and ultimately from the Latin capsa ("box"). The root is not related to the colonial British word "cash", which meant "Indian monetary system", and derived from the Tamil language kasu, Sanskrit karsha and Sinhalese kasi."To cash", the verbalization of the noun means "to convert to cash", as in the expression "to cash a cheque".