What is the difference between food spoilage and food poisoning?

Food poisoning is generally the result of when the food hasn't been cooked properly or has been contaminated with a substance (for example blood from raw chicken dropping on it) food spoilage is when the food has gone off (past it's sell by date). You can generally tell when spoilage has occurred as it will look or smell different (e.g fruit will go mouldy) but it can be hard to tell when a food has been contaminated as it may not look or smell different but you will know later on when you are throwing up and so have food poisoning!