What does “social butterfly” mean?

A social butterfly is someone who flits between groups at a party, chatting with everyone rather than sticking with one circle. The English idiom borrows the restless way a butterfly moves between flowers and turns it into a portrait of an outgoing, sociable person. The phrase carries a warm or teasing tone, depending on whether you envy the person or wish they would slow down. American English picked it up in the early 1900s and it has stayed in everyday use across sitcoms, magazine quizzes, and dating shows.

In this clip, an English-speaking couple plays a fourteen-question quiz: “Who’s the social butterfly?”