What is a stakeholder?

I am sorry to have given you the wrong information on this topic as I had the impression that a stakeholder is people from outside the organisation that have an interest in their business. But, to my surprise and mistake through further research to find out this: "A stakeholder is anyone with an interest in a business. Stakeholders are individuals, groups or organisations that are affected by the activity of the business." from http://www.bbc.co.uk/schools/gcsebitesize/business/environment/stakeholders1.shtml. Please just help confirm the fact on what is a stakeholder by posting your comment.