Paper money is typically backed by the government that issues it, which promises to accept it as payment for goods and services. In the past, paper money used to be backed by a specific commodity like gold or silver, but most countries have moved away from this system to a Fiat currency system where money has value because the government says it does.
the government
Floating currency.
Money, especially paper money, is backed by the gold reserves of the issuing bank
They got paid by paper money. Whitch was worth nothing because no precious metal backed it up.
Paper money can be printed, but if there is no value to back it up, the result is inflation. All money, not just the newly printed currency, loses its value. So it's not smart to just print more paper money than is backed up by real value.
Paper money is typically backed by the government that issues it, which guarantees the value of the currency. In the past, many countries pegged their currency to a specific amount of gold or silver, known as the gold standard, but most countries now operate on a fiat money system where the value of the currency is not backed by a physical commodity.
If the money is not backed up by something, it is just paper. The US used to back all of its paper money with gold or silver. Just printing money without something to support it leads to rampant inflation.
Faith that the currency will be accepted by those who offer goods and services for sale. In other words a good track record.
Because usually it is not backed up by any commodity such as gold or silver. While it is possible to have digital currency that is fully backed up by a commodity, most aren't.
It is unlikely that gold will replace paper money as the primary form of currency. Paper money is more convenient for everyday transactions and is backed by governments. Gold is more commonly used as a store of value or investment asset.
Most banks are fincially backed and your money is insured up to 250,000. Even if the bank went under the FDIC will right you a check as soon as the paper work is processed.
To combat inflation and deflation. Money was backed bt gold then which made hoarding of it by citizens a threat to the value of paper money and other commoditties