This is a trait that is often misunderstood, much because of the daily names given to this trait.

The silver trait, genetically called the inhibitor trait, is a trait that suppresses the color at the base of the hair so which makes the bottom of the hair pure white. 

What makes it confusing for those new to colors in cats are that this trait is given different names depending on if the cat is an agouti (with pattern) or a non-agouti (without pattern).

Let's take a black cat as an example, let's say you got a black cat and you add the silver trait, you will then get a "Black smoke", if you instead got a Black tabby and add the same trait it will be called a "Black silver tabby", it's the same trait it will be inherited the same way express the same way, just two different names for the same trait. We sometimes hear people say they got a black smoke tabby, this shows how confusing this is for new breeders and owners. 

For some reason shaded is also a trait that's been misunderstood and thought to be connected with the silver trait which is wrong, shaded is one name for the Wideband trait which can express itself on non-silver as well as on silver cats and has actually nothing to do with the inhibitor gene itself.
But this will be brought up more closely in another article.

I will not bring up all the different patterns and colors, I will just use black as an example.

 lexie ns 01  20210821 lyon 04
 This is a very good example of a Blacksmoke!
A good black smoke should appear black when looking at it, it's first when
the fur moves you would see the very pure bright white base of the coat.
A Blacksmoke should have 50% white.
 A Blacksilvertabby on the other hand got banded hair, they should also have 50% silver.
A silver tabby with more white at the base might be wideband, not enough to be shaded,
but they might have the wideband trait. However, it might also be just polygenes.