Dominos makes delicious pizza that makes a bad day great. Usually these pizzas can be cut into 8 slices especially with a large pie. If the pizza tastes as great as usual, 5 slices will disappear in a matter of seconds. Similarly, companies can offer shares of its stock in the market. When the company sells to the public (like when the pizza is delivered to the house), investors can purchase shares for a specific price (when hungry pizza lovers snag 5 slices).
If the company sold 5000 shares to public investors, there are now 5000 shares outstanding. In terms of the pizza, there are now 5 slices that are outstanding. If 3 additional slices were offered to guests, there would be 8 slices outstanding. It is important to note that companies can also issue more shares to the market if investors love the company as much as a slice of Dominos.