For jewelry, sterling silver is by far the most popular silver alloy in the world. Sterling silver, also called .925 silver, consists of 92.5 percent fine silver and 7.5 percent other metals (usually copper). Manufacturers use sterling silver because of its strength and durability.
Sterling silver is what's known as a metal alloy. This means that sterling silver is a combination of metals instead of just one single metal (like with pure silver, for example).