If you're good and hungry, and eating 5 handfuls of food in one sitting, and eating till you're full, its a meal.
If you're just nibbling away at a handful here and there, not really hungry, never really full, then you're snacking, and ignoring your body's messages. Hunger is your body asking for fuel. Food your body didn't ask for is food it doesn't need. How will you ever know if you're eating enough or too much?