Canning salt is a particular variety of salt that is used, as the name suggests, in canning. Canning salt is a fine-grained salt and is iodine-free. It also does not have the anti-caking ingredients used in regular table salt. The lack of additives means the canning salt will not turn vegetables — particularly pickles — a dark color, nor will it make their liquid cloudy. Pickles made with table salt would be perfectly safe to eat — they just wouldn’t look very pretty. Canning salt, on the other hand, produces a clear brine that is suitable for picking.
Leftover canning salt can be used as table salt, but without the anti-caking agents, this could pose a problem on humid days. One solution for this is to place a few grains of uncooked white rice in the salt shaker.
Sea salt is harvested from seawater through evaporation. Table salt is typically from rock salt, which is mined from mineral deposits. Both types of salt can be fully refined, and the end result is pure sodium chloride. Variations in the refining process result in different forms of salt.
Table salt is a fine-grained salt that often contains added iodine (iodized salt). Iodine is necessary for normal thyroid function. Some table salt may also contain anti-caking ingredient.
Sea salt is available in fine or coarse grain. Sea salt has a slightly different taste than table salt because of different minerals it contains. Many people prefer sea salt to table salt because they claim it has a more subtle flavor. Sea salt doesn't contain iodine or any other additives. However, if you use sea salt you typically don't have to worry about not getting enough iodine in your diet because iodine is available in many other foods, including dairy products, seafood and many processed foods.