Money, cash, currency, legal tender, specie, coin, coinage are comparable when they mean pieces of stamped metal or their equivalents issued by a government, or by an authority recognized by the government, to serve as a medium of exchange in the country or section under the control of that government.
Money applies to both coined gold, silver, copper, or other metal issued as a medium of exchange and to certificates or notes, often called specifically paper money, that sometimes promise payment in metal money, are issued by a government or governmentally recognized authority (as a bank), and pass like coined metal as a medium of exchange.
Cash applies to money, sometimes specifically called ready money, actually in hand or immediate possession of an individual or a business or institution.
Currency may apply to all of the money in circulation, as distinguished from that which is not in circulation for one reason or another, but it may also apply to paper money as distinguished from coined metal.
Legal tender applies specifically to the type of money which the law authorizes a debtor to offer and requires a creditor to receive as payment of money obligations and may or may not at any given time include all lawful money of a particular jurisdiction.
Specie, coin (only in a collective sense), and coinage apply only to minted or coined money; they therefore imply an opposition to all forms of paper money (as treasury notes and bank notes).