Sterling silver and silver are often used interchangeably, but they do not mean the same thing always.
Sterling silver is an alloy of silver containing 92.5% pure silver and 7.5% consists of other metals, usually copper. It’s because of 92.5%, it is often called 925 Sterling Silver.

Fine silver (99.9% purity) and pure silver is a soft metal on its own. Which means you can bend it, mold it, etc. Due to this softness, Silver on its own is not that great when it comes to durability and sturdiness. Therefore, to make those beautiful silver rings, silver earrings, etc., pure silver is often mixed with other metals to create an alloy. Alloys by nature are stronger and much more durable than their pure counterparts. In the case of silver, we can mix copper, zinc, or platinum to create Sterling silver.
History of Sterling Silver
Sterling silver originated in Europe. It was used as currency for commerce as early as the 12th century. By the 19th century, silversmiths began marking their silver pieces with an identification – maker’s mark, to distinguish themselves from other silversmiths and to guarantee the item. During the same time, silversmiths started earning a high position in the hierarchy of American artisans. This was mainly because of the level of skills needed to be a silversmith during the time.

Over time, sterling silver started being used in medical, currency, domestic use (tableware and jewelry) and in the musical instruments as well.
Sterling Silver and Tarnishing
In its pure form, silver is not that reactive but is prone to tarnishing. This happens due to the oxidation process with atmospheric pollution resulting in silver sulfide which slowly appears as black tarnish during exposure to airborne compounds of sulfur. Moreover, as the purity of silver decreases due to the introduction of other metals, the tarnishing, and corrosion increases.

Taking care of your sterling silver jewelry
Don’t worry, we have created a handy guide for you to make sure your beautiful silver pieces stay shiny and last longer. You can read more about it here – How to take care of your sterling silver jewelry.
Emerly’s silver jewelry
We are Emerly’s are dedicated to bringing luxury into your life at affordable prices. We ethically source and sell sterling silver rings, sterling silver earrings, sterling silver bracelets for women. Whether you are looking to buy sterling silver for yourself or ass a gift for your friend, you will surely find something at our store.
References: https://en.wikipedia.org/wiki/Sterling_silver