Entertaiment is a way to keep the attention of people, give them pleasure and delight. It can be an idea or a task, but it is more likely to be one of the activities or events that have developed over thousands of years specifically for the purpose of keeping people’s attention.
Entertainment can also stimulate the brain to realease seratonin and dopamine, wich is a good thing considering the brain was evolved to understand the world around us. Entertainment often hits on the themes that our minds was evolved to deeply react on such as backstabbing, murders and other social themes that were important for our survival in a social world.