A Money Market account is a cross between a certificate and a checking and typically pay a higher rate of interest than regular savings accounts. Furthermore, because they're NCUA-insured for up to $250,000 per depositor, they're a very safe investment, as you don't risk losing any of your principal.
A Money Market account works very similar to a checking account. Members may make unlimited deposits, withdrawals and transfers. This account is an attractive option for members to earn more interest while also keeping funds readily accessible if their situation changes.