1) Due diligence is an important process for investors to evaluate investment opportunities and reduce risk by identifying any issues or concerns. It involves investigating all aspects of a business including its market, management team, finances, legal structure, and product. 2) An investor should conduct due diligence before investing, when reviewing business plans and financial projections, when meeting the management team, and before finalizing any investment agreements. This ensures the business and deal terms still appear sensible. 3) Due diligence is a continuous process that helps investors determine if an opportunity is a good strategic and personal fit. It provides a reality check on an investment and opportunities to add value through the deal process.