Both are sodium chloride - NaCl. But they have different purity or grain size.
The size of the salt granule.
A serous difference doesn't exist.
Any serious difference exist between kosher salt and standard table salt.
Rock salt is in some ways similar to Coarse Salt, but do have differences, these are, rock salt is mined from underground deposits and goes through various processing techniques whilst coarse salt ( Kosher) is relatively pure and contains no iodine or any other additives.
what is difference in a gold ring and rock salt
nothing
Nutritionally there is no difference between these two types of salt. Kosher salt is a larger grain type of salt; it is certified Kosher and can be used to prepare meals, for home canning and can be ground to be used as a table salt.
You Really can't
Any difference, both are sodium chloride.
Almost all salt is kosher by default. The only issue would be if non-kosher additives such as flavourings were added to the salt. Sea salt is healthier than traditional table salt as the sodium level in sea salt is far lower.
Most people prefer rock salt to melt ice (sidewalks, driveways, etc) over table salt because it does not cake on the surface like table salt. As for effectiveness, they all combat ice the same. All edible salts are kosher unless something is added to them to render the salt non-kosher such as flavourings. There is no specific type of salt that is "kosher salt".
Kosher salt