What are the differences between bureau and office ?

‘Office’ refers to a room or building where people work sitting at desks. All kinds of companies and business have offices: banks, IT companies, lawyers etc. When a student misbehaves at school, he or she is usually sent to the principal’s office.
Some government departments are also called offices: the Home Office, the Foreign Office.
‘Bureau’ is an office that provides information on a particular subject. It usually refers to public administration offices: employment bureau, bureau of public affairs, bureau of public land administration, bureau of immigration etc.