Sea salt

Fleur de sel is French sea salt, so the answer to the first part of your question is that they are same thing.

Sea salts are distinguished by either the trace minerals or other additives. For example Hawaiian Alalea sea salt derives it’s pink color from the iron oxide (FeO2) that is so prevalent on the islands. Other salts have additives such as smoked salt, hickory salt, vanilla salt.

I find that having a healthy selection of salts on hand gives me the ability to finish dishes with some really nice flavors.

I frequently make tomato salad very simply. Grape tomatoes (in half) celery leaves, purple onion or scallions - just a couple, fresh basil and only olive oil (never vinegar). The difference sea salt makes is astounding.Your recommendation of a variety of sea salts is an excellent point. Thank you.