As a youngster, I did the things normal youngsters would do. I went to school, church, camp, scout meetings. At all of these places, if I did what was expected, many times I'd get a gold foil star.
When you're very young, the gold foil star itself is the reward. Do something good, get a star. Awesome!
Look! I got a gold star!
You'd lick it and slap it on your chest. Or your forehead. Or your hand. You wanted to show off that star. The star was recognition of your accomplishment in stacking blocks or singing a song. You wanted others to see it and recognize your coolness, too. It was mostly a boolean thing; you either had a star, or your didn't.
A little bit older, and the teacher started keeping a chart, proudly displayed beside the chalkboard. If you received a star, you didn't get to keep it and paste it on your body, though. Instead, you'd march up to the chart, and put it in its place next to your name. The gold foil star had become a measurement of competition.
Dude, Todd, I've got 4 more stars than you do.
It might ultimately culminate in a party at the end of the year, or a special field-trip for people with enough stars on the chart. In the idea of inclusiveness, it's normally a threshold model with the bar set relatively low.
A few years further down the road of life and the gold foil stars advance to being a type of currency. It even has its own exchange rate involving select real-world goods.
I'll give you a star every day you finish your homework before dinner. If you have 20 stars, I'll take you to the store to buy a CD.
Work becomes measured by the number of stars received compared to the value of the items available for "purchase" with them. Ultimately, it's a parentally-constrained currency system with a very limited market.
While gold foil stars are easily counterfeited, the reality of living with the treasury department makes it impractical.