Some people claim that Seal salt is better than Table salt (normal salt) because sea salt has lower sodium levels. However, this is a marketing gimmick. The major difference that exists between sea salt and table is texture, taste and the processing procedure.
Sea salt it obtained through evaporation of ocean water which leaves behind minerals that add flavor and color. On the other, hand table salt is obtained from underground salt deposits and processed to remove minerals. Potassium iodide and other minerals are also added to table salt.
Whichever you decide to use, make sure that you follow dietary guidelines.
Read more on how table salt is processed: http://www.madehow.com/Volume-2/Salt.html
From a nutrition point of view: https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/expert-answers/sea-salt/faq-20058512