Is "Kosher salt" supposed to be understood as certain salts that adhere to the Jewish religions dietary restrictions? I'm curious if this is so what about salt can make it kosher or non kosher?
Salt in and of itself is inherently Kosher. In most consumer and industrial applications, no kosher-sensitive ingredients are added to salt, so it can in fact be used without Kosher certification.
"Kosher salt" would actually be more properly named "Koshering salt." What is special about it is that it is coarse grained. This makes it suitable for preparing meat to be able to be cooked in a Kosher manner. In order for kosher meat to be cooked, it as to first be soaked, salted with coarse grained salt and rinsed in order to remove the blood. Standard table salt is too fine to be suitable.
Apparently some like the coarse grained property of the salt and use it instead of table salt.