Coins are struck in two different styles and for two distinctly different purposes. And they have been for centuries in mints right around the globe.
Coins are struck so that they can be used in every-day transactions. We call it circulating currency - coins that circulate.
Circulating coins are mass-produced in what can only be described as a factory environment and distributed through the banks at their face value.
Coins can also be struck to PROOF quality.
A PROOF coin is a specially made coin distinguished by sharpness of detail and usually with a brilliant mirror-like surface. A PROOF coin is never intended to be used. It is a collector’s item.
Proof coins are struck in highly controlled environments. The production is a painstakingly slow process. Coin blanks are hand-selected and they are polished to achieve a smooth mirror shine. The dies are also specially prepared to ensure the design is perfectly executed and crisp. Because the process is arduous, proof coins are always struck in limited numbers.
The confusing part for the novice is that proof coins look, essentially, the same as a coin struck for circulation. They share the same design. But there is a vast difference in the way in which they are produced. And the final product.
If you are in any doubt about whether your coin is a 'proof' coin, take it to your local coin shop where it can be sighted by a professional.