If users save their login credentials in Firefox's password manager, they are stored on disk in an encrypted format, but the key also is stored on disk so someone with physical access to the computer could decrypt them. They also can be viewed from inside Firefox. If the user wants to prevent those forms of access, they need to create a Primary Password.

• Manage your logins with the Firefox Password Manager
• Use a Primary Password to protect stored logins and passwords

Users also can choose to store an encrypted copy of their saved logins in the Mozilla Sync cloud. These credentials are encrypted before upload using a key based on their Mozilla Account password. There's probably an article on that.

Note that the above is about Firefox on desktop, Firefox on mobile devices do not use a Primary Password, but use OS authentication like Biometrics (fingerprint and face recognition) or the lock screen password.

The PP on desktop is used to encrypt the actual encryption key with an extra layer of encryption, while OS authentication like Windows Hello or Biometrics, that can Firefox possibly use if no PP is set, merely add an extra step to access the passwords.

Hi I'm not sure why you repeated the question and marked that reply as the solution. Can you please clarify this, so I can decide whether to close this question.

Thank You, My problem is Resolved and that Quotes is done by mistake