What is the difference between table salt and kosher salt?
Most salt shakers contain table salt, a fine-grained salt often including iodine - called iodized salt.  Table salt is most commonly applied “at the table” when eating, however many home cooks don’t tend to keep multiple types of salt on hand so they might season their food with table salt during the cooking process.  
Kosher salt is a more flaky salt and typically used either in larger quantities for brining or creating a salt crust on proteins prior to cooking.  Most professional chefs will choose Kosher salt over table salt as they prefer the texture and usability.  Table salt, being very fine-grained, is more dense than kosher salt and as such, recipes using salt should be weighed rather than using a volume measurement to ensure that a different type of salt doesn’t ruin the recipe.