The red berries are technically called drupes which means they are a fruit with a hard pit core surrounded by flesh like peaches and cherries. Although poisonous to people and pets they are a source of food for birds during winter. We must be putting out enough seed in our feeders as the birds that visit our yard have not eaten all the berries! For more info on a Chinese Holly see: https://plants.ces.ncsu.edu/plants/ilex-cornuta/