Is there a difference between silver and sterling silver?

Its a question of purity. Sterling silver is an alloy of silver containing 92.5% by mass of silver and 7.5% mass of other metals, usually copper.

Fine silver is 99.9% pure silver, but is generally too soft to use in jewelry.

Silver plate, on the other hand, is an extremely thin layer of silver over a base metal, usually copper, brass, or the like.

And if you just see "silver," you're most likely looking at an alloy that contains silver, but less than 92.5%