Basically, cryptocurrencies are entries about token in decentralized consensus-databases. They are called CRYPTOcurrencies because the consensus-keeping process is secured by strong cryptography. Cryptocurrencies are built on cryptography. They are not secured by people or by trust, but by math. It is more probable that an asteroid falls on your house than that a bitcoin address is compromised.
Money market funds offer high liquidity compared to other instruments with similar expected returns, like CD’s and treasury bills, while still being relatively low risk. You must typically hold a CD until its full maturity date to avoid paying an early withdrawal penalty. Treasury bills also have specific maturity dates. Money market funds, however, don’t have a set shelf life and can be liquidated on-demand when the cash is needed.
The money market consists of financial institutions and dealers in money or credit who wish to either borrow or lend. Participants borrow and lend for short periods, typically up to twelve months. Money market trades in short-term financial instruments commonly called "paper". This contrasts with the capital market for longer-term funding, which is supplied by bonds and equity.