It depends what kind of coarse salt it is. It could be coarse table salt, coarse sea salt, kosher salt, kosher sea salt, pretzel salt... there are many kinds of salt and some can be found in both coarse and fine grades.
Coarse salt is just common salt that has not been ground into the finer salt you are used to purchasing from the grocery store. Sea salt is taken from a sea and can be a coarse grind or can be finely ground, depending on your choice
Coarse Salt is basically a variety of salt it is usually larger than normal salt or table salt. Coarse Salt's particles are slightly thicker than fine salt. Coarse salt & the sea salt are both same,actually coarse salt is the synonyms for sea salt & the only difference between these two is the different particle sizes.