The clown at the birthday party, the Broadway show, the stadium rock concert, your friends fighting over the last potato chip—these are all examples of entertainment. Derived from the French word entretenir, to keep up or support, entertainment came to mean keeping happy guests, a role that is still important for hospitality and public life. Entertainment has evolved to accommodate any scale or context, from a private DVD choice for one person to global television spectacles with millions of viewers. And just as some activities once used in hunting or war have become spectator sports, so other forms of entertainment can develop into serious work and even serve a purpose such as social change or spiritual growth.