A festival could consist of a weekend of short plays or movies, or it could be an all-day series of musical events. A festival is any event consisting of numerous acts, especially one that lasts for a full day or several days.
The word festival can also imply “big party,” which refers to a celebration that typically lasts for a long time. There are religious festivals and seasonal/cultural ones, such as the Italian Heritage Festival in a city. Several well-known celebrations are Burning Man in the United States, Oktoberfest in Germany, Carnivale in Brazil, and the Fringe Festival in Scotland. You could do a festival hopping tour throughout the globe.