Collectible coins, particularly those from the United States, encompass various types, including commemorative issues, bullion coins, and circulating coins that were minted in limited quantities. The 2014 Denver minted coins, such as the presidential dollars or national park quarters, are popular among collectors for their unique designs and historical significance. A roll typically contains 50 coins and can represent a specific denomination or series, serving as both an investment and a collectible. The preservation state and rarity of these coins often significantly impact their value in the numismatic market.