Encryption of passwords in the database

As administrators, we noticed that sometimes we can see a user's password on the user detail page, other times it is not shown to us (see image).
Can you explain the reason for this behavior?

When a password was created during the registration process of a new user or it was edited on the page:
Overview => Edit User Details
... by the user herself / himself (as a personal password), the password will be encrypted in the database and is therefore not visible for administrators.
It cannot be sent via bulk e-mail, either.

When a password is entered or generated by a an administrator or organizer on behalf of a user on the page:
Overview => User and Participant Management => Create New User Account
... or has been imported using the import data function:
Overview => Data Import and Export => Import Data
... it will not yet be encrypted and is therefore visible to administrators.
Such passwords can be sent via the bulk e-mail function.