What do land snails need to survive?

Garden snails need water, air, and food to survive, just like us! For the water, though, it needs it not just to drink (I'm not so sure if they can actually drink) but to hydrate themselves. You may notice that Garden Snails come out when it rains outside. This is because they only are active when there is moisture, and when it isn't dry, or else they will dry out. Their food includes lots of veggies like lettuce, though I am sure that they eat fruits of all kinds too. They are herbivores. Also, they breath air, and they have a breathing hole too!