how are the relations between accounts table and notes, call history, contacts tables established in CRM Database?

how are the relations between accounts table and notes, call history, contacts tables established in CRM Database?

Hello,
Which field of the notes table and accounts table are used to join these 2 tables?
Which fields of the call history table and accounts table are used to join these 2 tables?
Which fields of the contacts table and accounts table are used to join these 2 table1?
Please guide me,
Thanks
Sara