There is a big difference in different types of salt. The first, and biggest difference, is the sodium to salinity (S/S) ratio. Iodized salt (table salt) has the highest sodium to salinity ratio, meaning it takes more of the actual salt to give it a salty taste. Kosher salt has a medium ratio, and sea salt usually has the highest ratio. This means that you will get more flavor from less sea salt than you will with iodized salt. This is also very important for people who have low-sodium dietary needs, as you can use less sodium and get the same taste. This is why you will not get the same flavor using iodized salt for a recipe that calls for kosher salt.
The second difference in salt is the size and shape of the grains. Notice how iodized salt is all the same size and very small, whereas kosher salt is usually very coarse grain? This affects not only the solvent time of the salt, but also your ability to consistently measure the same amount of salt with your hand. The grains of kosher salt make it the easiest to measure out by hand.
These properties of salt give different salts different uses. Iodized salt is more commonly use to finish salting fried foods, as it sticks to the surface of the food better. Kosher salt is used in most commercial kitchens because of the ease of measuring, and also because its shape and salinity allow for bleeding meat. Sea salt is most commonly used in desserts in order to balance the intense sweetness of some items.
For those wondering about the S/S metric of salts, it is caused by the different crystalline structure of salts. As salt forms, it doesn’t always form in the same crystal structure. This means that in some salts more sodium chloride (NaCL) molecules form in a more densely packed fashion. This causes a higher sodium content, and less taste because it breaks down slower in your saliva. The less densely packed molecules have less sodium per volume, and dissolve more rapidly in your saliva.