The French produce all the table salt they need in their saline springs or in their coastal salt pans, either along the Mediterranean (especially around Aigues-Mortes and the Camargue) and in sheltered spots along the Atlantic coast.
Fleur de sel or ‘flower of salt’ is the thin top crust of pyramidal crystals, often pale grey, formed on the seawater as it evaporates. Chefs love to add it to their dishes just before serving; as it is moister than regular salt, it lingers on the tongue longer. It also has a more complex taste as it is unrefined and includes other minerals such as calcium and magnesium chloride—which make salt taste saltier, so in theory you need less.
Images by Christian Mertes (Mudd1 12:28, 18 April 2007 (UTC), Demeester, World Imaging on Wikimedia Commons