Hi Ariel,
Please find below the difference between these object types:
Standard: The authorization values in the role are the same as those configured in SU24 for the relevant transaction/s.
Maintained: When authorization objects are maintained for a transaction code in SU24, but the field values are not fully defined, the object appears in the role with one or more empty fields. When these fields are updated the object status becomes "maintaned".
Changed: When the authorization object field values are changed from the values configured in SU24, the object status becomes "changed".
Manual: Authorization objects are added manually to roles to provide additional authorization in addition to authorization objects added automatically after adding t-codes in menu tab.
Hope this answers your question.
Thanks
Santosh