Inside Director
  
A company's board of directors can seem like a shadowy, amorphous blob. Just a bunch of similar people in similar clothes continuously voting unanimously in favor of world domination.
In real life, though, companies take some pains to assemble their boards. They want different skills and different perspectives, so that the firm has access to a wide range of experience.
Everyone might end up voting unanimously for world domination in the end. But first, individual board members will give some interesting opinions on how that domination should occur.
Inside vs. outside directors are one key distinction companies use to gain different perspectives among their board members. An inside director is an employee of the company, like the CEO or CFO. Someone from inside the company.
In contrast, an outside director comes from...somewhere else. They don't work with the company day-to-day, so they can give an outside perspective.