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Inside Director (Executive Director - in English)
Any member of a company's board of directors who is either an employee or stakeholder in the company.
Investopedia Says: Inside directors can either be management or major shareholders in the company.
Outside Director (Non-exec)
Any member of a company's board of directors who is not an employee or stakeholder in the company.
Investopedia Says: Outside directors are advantageous because they have very little conflict of interest.