Money Market vs High Yield Savings Why Different Interest Rates

With current current interest rates rising on bank accounts including cds, money market and savings accounts, there is a particular type of account that some banks appear to be paying a higher rate on. It’s the high yield savings, some use different names. Some are paying as much as cds. Which is impressive but also leads to the question of why are the rates so much higher on savings than money market accounts? Neither have a term associated with them.