What does Dependents mean?....im trying to create a broker accoutnt with tradeking and they ask for dependents?

in the set up of my account, they ask me for Dependents, adn i dont know what needs to be filled in?!?!?! they leave me 2 spaces to type something, so would it be my age? or please let me know what i need to fill in!! thanx

Dependents are people who depend on you for support, usually your children but not always. The ones you claim on your tax returns.