Coin history
Proof coins versus business strikes
Business strikes are made for circulation and produced in large numbers. Proof coins are struck from specially prepared dies and polished blanks to give sharp detail and mirror-like fields.
Proofs were sold directly to collectors in sets for many years. Because they were made with extra care, they are often more detailed than a business strike of the same design.
Check the packaging, the surface and the detail before you assume a coin is a proof. Many proofs look dramatically different from ordinary circulating coins.