salt

Sometimes I think my high school teacher was right: we really do live in pockets of ignorance.
Yesterday, while reading various chow-chow recipes, I kept coming across this ingredient: canning salt.
Now, I know there are different types of salt:

• iodized table salt - what I use
• non-iodized table salt - looks the same, but without iodine in it or on the box
• sea salt - which comes from the sea, looks like little rocks and is very popular in France
• kosher salt - which I've only seen and heard of, but have no idea how salt could be clean or unclean
• and rock salt - which is absolutely necessary for making homemade ice cream :)

So while I was at the grocery store, I looked, and sure enough there were boxes of canning salt. According to the box, it's best used when canning vegetables. For some reason the salt is absorbed better and doesn't discolor the veggies nor sink to the bottom of the jar. I decided to google it and see what more I could learn, but after reading one page decided I have no desire to be a salt connoisseur.

And now I'm curious: what kinds of salt do you use or prefer?