Some basic vocabulary about how companies are structured:

accounts Dept. : department responsible for administering a company´s financial affair.
A.G.M.UK : Annual General Meeting of a company´s shareholders.
board of directors : a group of people chosen to establish policy for and direct or control a company.
chairmanUK : person who heads a Board of Directors; head of a company; chairperson.
director : a member of the board of directors.
executive officerUS : person who manages the affairs of a corporation - chief executive officer n.
headquarters : a company´s principal or main office or centre of control.
manager : person responsible for day-to-day running of a dept.; executive officerUS.
managing directorUK : senior director after the chairman responsible for day-to-day direction.
Marketing Dept. : dept. responsible for putting goods on market, inc. packaging, advertising etc.
organisation chart : a table or plan showing a company´s structure graphically. 
Personnel Dept. : department responsible for recruitment and welfare of staff or employees. 
presidentUS : the highest executive officer of a company; head of a company. 
production Dept. : department responsible for physical creation of product. 
purchasing Dept. : department responsible for finding and buying everything needed by a company. 
reception : the place where visitors and clients report on arrival at a company. 
R & D Department : department responsible for Research and Development of (new) products. 
Sales Department : department responsible for finding customers and making sales. 
shareholder : person who holds or owns shares in or a part of a company or corporation.
vice presidentUS : any of several executive officers, each responsible for a separate division