In a company sense the definitions can be blurred. Heres one definition, but there are others.
A director is a member of the board of directors of the company, normally a shareholder, or co-opted by shareholders. The board sets the broad policy for the company and acts as the ultimate court of appeal within it. It is also normally held jointly and severally responsible for liabilities incurred by the company unless these have been limited.
An executive director is a hands-on director, someone involved in the day to day running of the company, often the actual boss, but if not then close to it.