what are the differences / similarities between 401(k) of USA and CPF of Singapore?

Answer 1

401(k) are managed by banks. You lose if they go bust. CPF is managed by the goverment who make sure you get as little of it back as possible eg conversion to annuity payable from age 62, expensive hospitals with hotel lobbies, constant reminder to encourage you to rent flats (99 year lease) at inflated value.