Are you talking about having several using the same computer account to use Firefox? Or each user having a separate account on the computer?

If the latter, each Firefox profile is located in the computer account of each user. One would need administrator privileges to get access to other accounts.

Each FF profile is totally separate from other profiles.

1 computer 1 account 4 people 1 fire fox with 4 different profiles

Dad = work mom = mom stuff bro = hes stuff me = my own stuff

when clicking on each profile before lunching fire fox can a different password be ask for dad or mom or bro or me ?

meaning if i don't have dads profile i cant see hes things and vice versa

profile password*

The only password Firefox uses is the Master Password for the Password Manager.

The method you describe will let any user use any profile. There would be no real privacy.

Make sure you have Administrator Privileges on your computer. Press the Windows icon. Then Control Panel > User Accounts. Create a normal user account for each user. Firefox will create a profile for each user in the user's folder.

so in the new version of fire fox there is no way to create a individual password per profile like the old version ?

Not from one computer account, other than the Master Password. The Master is only for the Password Manager.

https://support.mozilla.org/en-US/kb/use-master-password-protect-stored-logins Use a Master Password to protect stored logins and passwords