What are the three paradigms of the database

1, three database paradigm what
the first paradigm: the column can not be divided
second paradigm: row may uniquely identify the primary key constraint
third paradigm: the non-primary property sheet can not rely on the non-primary property other tables foreign key constraint
and three The grand paradigm is dependent on the first level, the second paradigm is based on the first paradigm, and the third paradigm is based on the first and second paradigms.