Improvisation, or improv, is the art of making something up on the spot, whether it be a song, character, dialogue, or entire story. The actors who make everything up are called improvisers. Frequently, improvisers will ask an audience for a suggestion to begin the show.
Improv is spontaneous, live theater without a script. It’s exciting and imaginative. Each improv performance is original. There is no one in the back of the theater scribbling down the lines of dialogue for the future. When the show is over, there’s never going to be a performance quite like that one.