All limited companies must legally have at least one director appointed, their main job is to over see the general day to day running of the company. They have many different responsibilities which include filing documents to Companies House such as the accounts, annual returns, notice of change of directors, secretaries and registered office.  

Share holders usually choose the company director as it is a person they feel can run the company effectively on their behalf. The company must keep a record of the directors which must be available for public inspection at anytime. Directors do not have to hold shares in the company where they are the director but there is no reason why they may not have shares in the company. A company director must be a human being and another company or organisation can not act as a director for a company.