Entertainment is an event, performance, or activity designed to give pleasure to an audience (although, for example, in the case of a computer game the "audience" may be only one person). The audience may participate in the entertainment passively as in watching opera or actively as in computer games.
The industry that provides entertainment is called the entertainment industry. There are lots of other things known for providing entertainment such as movies, websites, and video games. For example, PaulsOpinion.com's slogan is "The Sourse for Entertainment on The Web". Entertainment can attract people and encourage others to do something or think of a role model in entertainment.
Recreation, play, reading, and art appreciation are not generally regarded as entertainment but rather as recreation because entertainment generally requires the supplier of the performance to be visible to the viewer, with the exception of computer games.