De Beers is a company that sells shiny things called diamonds. They are found underground and are really hard and sparkly. De Beers makes sure that they are the only ones who can sell lots of diamonds. They do this by buying up lots of diamond mines and telling people that diamonds are really rare and special. They even made up a special way to measure how good a diamond is called the 4 Cs: cut, clarity, color, and carat weight. This makes people think that diamonds are super important and valuable. People like to give diamonds to show that they love someone a lot or for special occasions like weddings. So, De Beers makes lots of money by selling these shiny things and convincing people that they are really special.