Overeating when people eat a lot of food all the time. Binge eating is when you eat very little for ages and then you stuff yourself with food until you feel bloated.
It is a fine line between the two. And there are people who do both. Overeating is eating beyond what you need- eating when you're no longer hungry. Overeating is common -everyone has an occasion where we eat an extra piece of pizza or have that big dessert. When people overeat on a regular basis- that is when it becomes a problem. Chronic overeaters are usually overweight. It's not a specific stressful event that triggers the overeating- it's more related to reward and pleasure thing. Chronic overeaters are often looking for comfort and solace in food. Binge-eaters, as VC indicated are compulsive and often diet or undereat then have an enormous meal. Binge-eaters live on a cycle of denial and binging. Binge-eaters sometimes throw-up after the big meal- either intentionally or because the meal makes them sick. Binge-eating is often triggered by specific stressful events- a breakup, a fight with someone, bad news, etc. Binge-eating can be quite dramatic- whole pies, dozens of cookies, entire boxes of chocolates, etc. Binge-eaters will often be of normal weight because the behavior only occurs every now and then and in some cases because they throw up immediately after the binge.