The Casino

For every game there are two sides: the player and the owner. Both sides are attempting to make money from the same game. For the player, it is entertainment but for the owner it is a business. What separates the two are the odds or the margin of safety. For the player it is against him. For the owner it is with him. If the player forgets this fact, he courts disaster. If the owner forgets this fact he may behave foolishly and, therefore, not do as well as he could.

The analogy describes the difference between the speculator(player) and the investor(owner).