The Agents of Improv

I dunno...wing it.

Short-form improv: Short form improv usually takes the form of games with set rules for how the scene will proceed. The improvisers might be limited to sentences three words long, or required to avoid a particular letter of the alphabet, or assigned a specific character quirk to act out over the course of the scene.
Long-form improv: Long form improvisation is more about developing a character and finding a plot or story than short form, which is often played just for laughs. Requiring a totally different attitude, long form often allows an entire hour of improv to evolve from just one word or phrase.
Urban improv: Urban improv is a form of improv performed in public places. While urban is highly varied, it usually takes the form of a few improvisers breaking outside of social norms in a harmless, entertaining way. Audience members at these events may find themselves watching people in business suits skipping through the room, helping prepare for a surprise birthday party on a bus, or even caught in a time loop in a café.