They are certainly not synonymous:
Registration and title fees are legitimate and should be paid and is what the dealer is paying to the DMV for registering your new car.
But documentation/administrative fee are just arbitrary fees the dealer is making up to cover for "administrative" "documentation" fees to cover their expenses for paperwork etc ... needless to say this is just a shitty excuse for the dealer to have another helping to your money. In fact you should not pay this at all. I would refuse to pay this or walk away. They already get their margin on MSRP.