--This OP has been edited. Good background can be found here (courtesy APMEX): https://www.apmex.com/education/investing/what-is-the-difference-between-a-coin-and-a-round
In the United States there is a distinction between silver coins and rounds. A "coin" is a reserved term deriving from the Coinage Clause of the Constitution (Article 1, Section 8, Clause 5).
Silver coins
Below is a Canadian Maple Leaf and an American Silver Eagle.
I appreciate the Maple Leaf's 4 nines fine Ag. That sets it apart in a fine way. Although the Silver Eagle is a classic.
Silver rounds
Minted by private mints and not affiliated with the US federal government. The distinction between a Coin and a Round is an important one to keep in mind while stacking the shiny metal. Counterfeiting becomes an issue if there is evidence the piece is passing itself as inauthentic legal tender.
Here is a SilverShield Round (not legal tender).
Rear:
Front:
Between the three, which do you prefer?