the entity is still the same, apple, inc. 
apple inc can choose how many of its shares are available on the public market, or undistributed, or distributed to existing shareholders. So assume 50% of shares are distributed (assume 500M shares for simplicity sake), they gradually buy back shares, and the outstanding shares can either be worth more or less (usually more).<p>In the case of Dell, Michael Dell was the largest independent shareholder, he partnered with a private equity firm to buy outstanding shares back, and then the Dell, inc. entity has to pay back the private equity firm with revenues from sales and sales of assets.