Money market account

What is a money market account ? Savings bond trust fund IRA all of those ? I’m 20 and I don’t know a DAMN Thing about the real world but I’m willing to learn . I have 2 kids I’m trying to have us set financially . I work at a call center and I fill out credit card applications and one of the questions I have to ask them is “what is the total combined balance of your checking , savings or money market account” with the bank . But WHAT is a money market . And what do you have ? And how does it work ? I should I determine what to do ? I don’t wanna just have a checkings and saving I wanna invest that’ll help me in the long run .